Numerical prefix
Encyclopedia
Number prefixes are prefix
es derived from number
s or numeral
s. In English and other European languages, they are used to coin numerous series of words, such as unicycle – bicycle – tricycle, dyad – triad – decade, biped – quadruped, September – October – November – December, decimal – hexadecimal, sexagenarian – octogenarian, centipede – millipede, etc. There are two principal systems, taken from Latin
and Greek
, each with several subsystems; in addition, Sanskrit
occupies a marginal position. There is also an international set of SI prefix
es, which are used in the metric system
, and which for the most part are either distorted from the forms below or not based on actual number words.
The cardinal series are derived from cardinal numbers, such as English one, two, three. The multiple series are based on adverbial numbers like English once, twice, thrice. The distributives originally meant one each, two each or one by one, two by two, etc., though that meaning is now frequently lost. The ordinal series is based on ordinal number
s such as English first, second, third. For numbers higher than 2, the ordinal forms are also used for fractions; only the fraction ½ has special forms.
For the hundreds, there are competing forms: those in -gent-, from the original Latin, and those in -cent-, derived from centi- etc. plus the prefixes for 1–9.
For Latinate 21, 22, etc., the pattern for the teens is followed: unvigint-, duovigint-, etc. For higher numbers, the reverse order may be found: 36 trigintisex-. For Greek, the word kai 'and' is used: icosikaihena-, icosikaidi-, pentacontakaipenta-, etc. In these and in the tens, the kai is frequently omitted, though not in triskaidekaphobia
. (The inconsistency of triskaidekaphobia with the table above is explained by the fact that the Greek letter kappa
can be transliterated either "c" or "k".) Sesqui- is used in Latin combinations for 1½ (sesquicentennial) and quasqui- for 1¼; multi- and poly- are used in Latin and Greek combinations for 'many' (multilateral, polygon). In chemical nomenclature
, 11 is generally mixed Latin-Greek undec-, and the 20s are based on -cos-, for example tricos- for 23.
Because of the common inheritance of Greek and Latin roots across the Romance languages, the import of much of that derived vocabulary into non-Romance languages (such as into English
via Norman French
), and the borrowing of 19th and 20th century coinages into many languages, the same numerical prefixes occur in many languages.
Numerical prefixes are not restricted to denoting integers. Some of the SI prefixes denote negative powers of 10, i.e. division by a multiple of 10 rather than multiplication by it. Several common-use numerical prefixes denote vulgar fractions.
Words comprising non-technical numerical prefixes are usually not hyphenated. This is not an absolute rule, however, and there are exceptions. (For example: quarter-deck occurs in addition to quarterdeck.) There are no exceptions for words comprising technical numerical prefixes, though. Systematic name
s and words comprising SI prefix
es and binary prefixes are not hyphenated, by definition.
Nonetheless, for clarity, dictionaries list numerical prefixes in hyphenated form, to distinguish the prefixes from words with the same spellings (such as duo- and duo).
Several technical numerical prefixes are not derived from words for numbers. (mega- is not derived from a number word, for example.) Similarly, some are only derived from words for numbers inasmuch as they are word play
. (Peta- is word play on penta-, for example. See its etymology for details.)
The root language of a numerical prefix need not be related to the root language of the word that it prefixes. Some words comprising numerical prefixes are hybrid word
s.
In certain classes of systematic names, there are a few other exceptions to the rule of using Greek-derived numerical prefixes. The IUPAC nomenclature of organic chemistry
, for example, uses the numerical prefixes derived from Greek, except for the prefix for 9 (as mentioned) and the prefixes from 1 to 4 (meth-, eth-, prop-, and but-), which are not derived from words for numbers. These prefixes were invented by the IUPAC, deriving them from the pre-existing names for several compounds that it was intended to preserve in the new system: methane (via methyl which is in turn from the Greek word for wine), ethane (from ethyl coined by Justus von Liebig
in 1834), propane (from propionic which is in turn from pro- and the Greek word for fat), and butane (from butyl which is in turn from butyric which is in turn from the Latin word for butter).
Prefix
A prefix is an affix which is placed before the root of a word. Particularly in the study of languages,a prefix is also called a preformative, because it alters the form of the words to which it is affixed.Examples of prefixes:...
es derived from number
Number
A number is a mathematical object used to count and measure. In mathematics, the definition of number has been extended over the years to include such numbers as zero, negative numbers, rational numbers, irrational numbers, and complex numbers....
s or numeral
Numeral
The term numeral can refer to:* Symbols for numbers used in mathematics.* Numeral , the basic words combined in a language represent numbers* Numerical digit, the glyphs used to represent numerals...
s. In English and other European languages, they are used to coin numerous series of words, such as unicycle – bicycle – tricycle, dyad – triad – decade, biped – quadruped, September – October – November – December, decimal – hexadecimal, sexagenarian – octogenarian, centipede – millipede, etc. There are two principal systems, taken from Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
and Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
, each with several subsystems; in addition, Sanskrit
Sanskrit
Sanskrit , is a historical Indo-Aryan language and the primary liturgical language of Hinduism, Jainism and Buddhism.Buddhism: besides Pali, see Buddhist Hybrid Sanskrit Today, it is listed as one of the 22 scheduled languages of India and is an official language of the state of Uttarakhand...
occupies a marginal position. There is also an international set of SI prefix
SI prefix
The International System of Units specifies a set of unit prefixes known as SI prefixes or metric prefixes. An SI prefix is a name that precedes a basic unit of measure to indicate a decadic multiple or fraction of the unit. Each prefix has a unique symbol that is prepended to the unit symbol...
es, which are used in the metric system
Metric system
The metric system is an international decimalised system of measurement. France was first to adopt a metric system, in 1799, and a metric system is now the official system of measurement, used in almost every country in the world...
, and which for the most part are either distorted from the forms below or not based on actual number words.
Table of number prefixes in English
In the following prefixes, a final vowel is normally dropped before a root that begins with a vowel, with the exceptions of bi-, which is bis- before a vowel, and of the other monosyllables, du-, di-, dvi-, tri-, which are invariable.The cardinal series are derived from cardinal numbers, such as English one, two, three. The multiple series are based on adverbial numbers like English once, twice, thrice. The distributives originally meant one each, two each or one by one, two by two, etc., though that meaning is now frequently lost. The ordinal series is based on ordinal number
Ordinal number
In set theory, an ordinal number, or just ordinal, is the order type of a well-ordered set. They are usually identified with hereditarily transitive sets. Ordinals are an extension of the natural numbers different from integers and from cardinals...
s such as English first, second, third. For numbers higher than 2, the ordinal forms are also used for fractions; only the fraction ½ has special forms.
For the hundreds, there are competing forms: those in -gent-, from the original Latin, and those in -cent-, derived from centi- etc. plus the prefixes for 1–9.
| Number | | Latin prefixes | |Greek prefixes | |Sanskrit | ||||
|---|---|---|---|---|---|---|---|
| Cardinal | Multiple | Distributive | Ordinal | Cardinal | Multiple | ||
| ½ | semi- | demi- | — | hemi- | |||
| 1 | uni- | sim- | singul- | prim- | hen- | mono-, haplo- | eka- |
| 1¼ 1½ |
quasqui- sesqui- |
||||||
| 2 | du- | bi-, bis- | bin- | second- | di-, dy-, duo- | dis- | dvi- |
| 3 | tri- | ter- | tern- | terti- | tri- | tris- | tri- |
| 4 | quadri-, quadru- |
quater- | quatern- | quart- | tetra- | tetrakis- | chatur- |
| 5 | quinque- | quin- | quint- | penta- | pentakis- | pancha- | |
| 6 | sexa- | sen- | sext- | hexa- | hexakis- | shat- | |
| 7 | septem-, septi- | septen- | septim- | hepta- | heptakis- | sapta- | |
| 8 | octo- | octon- | octav- | ogdo-, octa-, octo- |
octakis- | ashta- | |
| 9 | novem- | noven- | nona- | ennea- | enneakis- | navam- | |
| 10 | decem-, dec- | den- | decim- | deca- | decakis- | dasham- | |
| 11 | undec- | unden- | undecim- | hendeca- | undecakis- | ekadasham- | |
| 12 | duodec- | duoden- | duodecim- | dodeca- | dodecakis- | dvadasham- | |
| 13 | tredec-, etc. | triskaideca- | tridecakis- | trayodasham- | |||
| 14 | quattuordec- | tetrakaideca- | tetradecakis- | chaturdasham- | |||
| 15 | quinquadec-, quindec- | quinden- | quindecim- | pentakaideca- | pentadecakis- | panchadasham- | |
| 16 | sedec-, sexdec- (but hexadecimal) |
hexakaideca-, hexadeca- |
hexadecakis- | ||||
| 17 | septendec- | heptakaideca- | |||||
| 18 | octodec- | octakaideca- | |||||
| 19 | novemdec-, novendec- |
enneakaideca- | |||||
| 20* | viginti- | vicen-, vigen- |
vigesim- | icosa-, icosi-, eicosa- |
eicosakis- | ||
| 30 | triginti- | tricen- | trigesim- | triaconta- | |||
| 40 | quadraginti- | quadragen- | quadragesim- | tetraconta- | |||
| 50 | quinquaginti- | quinquagen- | quinquagesim- | pentaconta- | |||
| 60 | sexaginti- | sexagen- | sexagesim- | hexaconta- | |||
| 70 | septuaginti- | septuagen- | septuagesima- | heptaconta- | |||
| 80 | octogint- | octogen- | octogesim- | octaconta- | |||
| 90 | nonagint- | nonagen- | nonagesim- | enneaconta- | |||
| 100 | centi- | centen- | centesim- | hecato-, hecatont- |
|||
| 200 | ducenti- | ducen-, bicenten- |
diacosioi- | ||||
| 300 | trecenti- | trecen-, tercenten-, tricenten- |
triacosioi- | ||||
| 400 | quadringenti- | quadringen-, quatercenten-, quadricenten- |
tetracosioi- | ||||
| 500 | quingent-, quincent- |
quingen-, quingenten-, quincenten- |
quingentesim- | pentacosioi- | |||
| 600 | sescenti-, sexcenti- | sescen-, sexcenten- |
hexacosioi- | ||||
| 700 | septingenti- | septingen-, septingenten-, septcenten- |
heptacosioi- | ||||
| 800 | octingenti- | octingen-, octingenten-, octocenten- |
octacosioi- | ||||
| 900 | nongenti- | nongen- | enneacosioi- | ||||
| 1000 | milli- | millen- | millesim- | chili- | |||
| 10,000 | — | myria- | |||||
For Latinate 21, 22, etc., the pattern for the teens is followed: unvigint-, duovigint-, etc. For higher numbers, the reverse order may be found: 36 trigintisex-. For Greek, the word kai 'and' is used: icosikaihena-, icosikaidi-, pentacontakaipenta-, etc. In these and in the tens, the kai is frequently omitted, though not in triskaidekaphobia
Triskaidekaphobia
Triskaidekaphobia is fear of the number ; it is a superstition and related to a specific fear of Friday the 13th, called paraskevidekatriaphobia or friggatriskaidekaphobia.The term was first used by Isador Coriat in Abnormal...
. (The inconsistency of triskaidekaphobia with the table above is explained by the fact that the Greek letter kappa
Kappa
Kappa is the 10th letter of the Greek alphabet, used to represent the voiceless velar stop, or "k", sound in Ancient and Modern Greek. In the system of Greek numerals it has a value of 20. It was derived from the Phoenician letter Kaph...
can be transliterated either "c" or "k".) Sesqui- is used in Latin combinations for 1½ (sesquicentennial) and quasqui- for 1¼; multi- and poly- are used in Latin and Greek combinations for 'many' (multilateral, polygon). In chemical nomenclature
IUPAC nomenclature of organic chemistry
The IUPAC nomenclature of organic chemistry is a systematic method of naming organic chemical compounds as recommended by the International Union of Pure and Applied Chemistry . Ideally, every possible organic compound should have a name from which an unambiguous structural formula can be drawn. ...
, 11 is generally mixed Latin-Greek undec-, and the 20s are based on -cos-, for example tricos- for 23.
Occurrences
- Numerical prefixes occur in 19th-, 20th-, and 21st-century coinages, mainly the terms that are used in relation to or that are the names of technological innovations, such as hexadecimal and bicycle. Also used in medals that commemorate an anniversaryAnniversaryAn anniversary is a day that commemorates or celebrates a past event that occurred on the same day of the year as the initial event. For example, the first event is the initial occurrence or, if planned, the inaugural of the event. One year later would be the first anniversary of that event...
, such as sesquicentennial (150 years), centennial (100 years), or bicentennial (200 years). - They occur in constructed words such as systematic nameSystematic nameA systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection...
s. Systematic names use numerical prefixes derived from Greek, with one principal exception, nona-. - They occur as prefixes to units of measure in the SISiSi, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...
system. See SI prefixSI prefixThe International System of Units specifies a set of unit prefixes known as SI prefixes or metric prefixes. An SI prefix is a name that precedes a basic unit of measure to indicate a decadic multiple or fraction of the unit. Each prefix has a unique symbol that is prepended to the unit symbol...
. - They occur as prefixes to units of computer data. See binary prefixes.
- They occur in words in the same languages as the original number word, and their respective derivatives. (Strictly speaking, some of the common citations of these occurrences are not in fact occurrences of the prefixes. For example: millennium is not formed from milli-, but is in fact derived from the same shared Latin root – mille.)
Because of the common inheritance of Greek and Latin roots across the Romance languages, the import of much of that derived vocabulary into non-Romance languages (such as into English
English language
English is a West Germanic language that arose in the Anglo-Saxon kingdoms of England and spread into what was to become south-east Scotland under the influence of the Anglian medieval kingdom of Northumbria...
via Norman French
Norman language
Norman is a Romance language and one of the Oïl languages. Norman can be classified as one of the northern Oïl languages along with Picard and Walloon...
), and the borrowing of 19th and 20th century coinages into many languages, the same numerical prefixes occur in many languages.
Numerical prefixes are not restricted to denoting integers. Some of the SI prefixes denote negative powers of 10, i.e. division by a multiple of 10 rather than multiplication by it. Several common-use numerical prefixes denote vulgar fractions.
Words comprising non-technical numerical prefixes are usually not hyphenated. This is not an absolute rule, however, and there are exceptions. (For example: quarter-deck occurs in addition to quarterdeck.) There are no exceptions for words comprising technical numerical prefixes, though. Systematic name
Systematic name
A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection...
s and words comprising SI prefix
SI prefix
The International System of Units specifies a set of unit prefixes known as SI prefixes or metric prefixes. An SI prefix is a name that precedes a basic unit of measure to indicate a decadic multiple or fraction of the unit. Each prefix has a unique symbol that is prepended to the unit symbol...
es and binary prefixes are not hyphenated, by definition.
Nonetheless, for clarity, dictionaries list numerical prefixes in hyphenated form, to distinguish the prefixes from words with the same spellings (such as duo- and duo).
Several technical numerical prefixes are not derived from words for numbers. (mega- is not derived from a number word, for example.) Similarly, some are only derived from words for numbers inasmuch as they are word play
Word play
Word play or wordplay is a literary technique in which the words that are used become the main subject of the work, primarily for the purpose of intended effect or amusement...
. (Peta- is word play on penta-, for example. See its etymology for details.)
The root language of a numerical prefix need not be related to the root language of the word that it prefixes. Some words comprising numerical prefixes are hybrid word
Hybrid word
A hybrid word is a word which etymologically has one part derived from one language and another part derived from a different language.-Common hybrids:The most common form of hybrid word in English is one which combines etymologically Latin and Greek parts...
s.
In certain classes of systematic names, there are a few other exceptions to the rule of using Greek-derived numerical prefixes. The IUPAC nomenclature of organic chemistry
IUPAC nomenclature of organic chemistry
The IUPAC nomenclature of organic chemistry is a systematic method of naming organic chemical compounds as recommended by the International Union of Pure and Applied Chemistry . Ideally, every possible organic compound should have a name from which an unambiguous structural formula can be drawn. ...
, for example, uses the numerical prefixes derived from Greek, except for the prefix for 9 (as mentioned) and the prefixes from 1 to 4 (meth-, eth-, prop-, and but-), which are not derived from words for numbers. These prefixes were invented by the IUPAC, deriving them from the pre-existing names for several compounds that it was intended to preserve in the new system: methane (via methyl which is in turn from the Greek word for wine), ethane (from ethyl coined by Justus von Liebig
Justus von Liebig
Justus von Liebig was a German chemist who made major contributions to agricultural and biological chemistry, and worked on the organization of organic chemistry. As a professor, he devised the modern laboratory-oriented teaching method, and for such innovations, he is regarded as one of the...
in 1834), propane (from propionic which is in turn from pro- and the Greek word for fat), and butane (from butyl which is in turn from butyric which is in turn from the Latin word for butter).
Cardinal Latin series
- unicycle, bicycle, tricycle, quadricycle
- uniped, biped, triped, quadruped, centipede, millipede
Distributive Latin series
- unary, binary, trinary, quaternary, quinary, senary, ... vicenary ... centenary ...
- quinquagenarian, sexagenarian, septuagenarian, octogenarian, nonagenarian, centenarian, ... millenarian
Greek series
- pentanePentanePentane is an organic compound with the formula C5H12 — that is, an alkane with five carbon atoms. The term may refer to any of three structural isomers, or to a mixture of them: in the IUPAC nomenclature, however, pentane means exclusively the n-pentane isomer; the other two being called...
, hexaneHexaneHexane is a hydrocarbon with the chemical formula C6H14; that is, an alkane with six carbon atoms.The term may refer to any of four other structural isomers with that formula, or to a mixture of them. In the IUPAC nomenclature, however, hexane is the unbranched isomer ; the other four structures...
, heptaneHeptanen-Heptane is the straight-chain alkane with the chemical formula H3C5CH3 or C7H16. When used as a test fuel component in anti-knock test engines, a 100% heptane fuel is the zero point of the octane rating scale...
, octaneOctaneOctane is a hydrocarbon and an alkane with the chemical formula C8H18, and the condensed structural formula CH36CH3. Octane has many structural isomers that differ by the amount and location of branching in the carbon chain...
, nonaneNonaneNonane is a linear alkane hydrocarbon with the chemical formula C9H20.Nonane has 35 structural isomers. Tripropylene is a mixture of three specific isomers of nonane.Its substituent form is nonyl. Its cycloalkane counterpart is cyclononane, ....
, decaneDecaneDecane is an alkane hydrocarbon with the chemical formula CH38CH3.75 structural isomers of decane exist, all of which are flammable liquids. Decane is one of the components of gasoline . Like other alkanes, it is nonpolar and therefore will not dissolve in polar liquids such as water...
, ... eicosaneEicosaneIcosane is an alkane with the chemical formula C20H42. It has 366,319 constitutional isomers.... - monopodMonopodA monopod, also called a unipod, is a single staff or pole used to help support cameras, video cameras, binoculars, rifles or other precision instruments in the field.-Camera and imaging use:...
, bipodBipodA bipod is a support device that is similar to a tripod or monopod, but with two legs. It provides significant stability along two axes of motion .-Firearms:...
, tripodTripodA tripod is a portable three-legged frame, used as a platform for supporting the weight and maintaining the stability of some other object. The word comes from the Greek tripous, meaning "three feet". A tripod provides stability against downward forces, horizontal forces and moments about the...
, tetrapodTetrapodTetrapods are vertebrate animals having four limbs. Amphibians, reptiles, birds and mammals are all tetrapods; even snakes and other limbless reptiles and amphibians are tetrapods by descent. The earliest tetrapods evolved from the lobe-finned fishes in the Devonian...
, hexapod, octopod, decapodDecapodSeveral things share the name decapod, from the Greek decapoda meaning "ten-legged":*Crustaceans in the Order Decapoda, such as lobsters and crabs*Several steam locomotive wheel arrangements were also called Decapods, especially the 2-10-0... - monadMonad-Philosophy:*Monad a term meaning "unit" used variously by ancient philosophers from the Pythagoreans to Plato, Aristotle, and Plotinus to signify a variety of entities from a genus to God....
, dyadDyadDyad may refer to:*Dyad , a pair of sister chromatids occurring in prophase I of meiosis; may also be used to describe protein morphology*Dyad , Greek philosophers' principle of "twoness" or "otherness"...
, triadTriadTriad is a term used to describe many branches of Chinese criminal organizations based in Hong Kong, Vietnam, Macau, Taiwan, China, and also in countries with significant Chinese populations, such as Malaysia, Singapore, the United States, Canada, Australia and the United Kingdom...
, tetradTetradTetrad may refer to:* Tetrad , Bivalents or Tetrad of homologous chromosomes consisting of four synapsed chromatids that become visible during the Pachytene stage of meiotic prophase...
, pentadPentadThe pentad was a Pythagorean term for the quantity of five.-See also:*Related greek numerical terms**Monad **Dyad **Triad **Tetrad **Decad *Other...
, hexad, heptad, ogdoadOgdoadIn Egyptian mythology, the Ogdoad were eight deities worshipped in Hermopolis during what is called the Old Kingdom, the third through sixth dynasties, dated between 2686 to 2134 BC...
, enneadEnneadThe Ennead was a group ofnine deities in Egyptian mythology. The Ennead were worshipped at Heliopolis and consisted of the god Atum, his children Shu and Tefnut, their children Geb and Nut and their children Osiris, Isis, Horus, Set and Nephthys.-Terminology:Egyptian mythology established multiple...
, decadDecadPythagorus regarded the number 10, or "decad" as being a perfect number, which was often represented by the tetractys, which embraced the whole nature of number....
(e), ... triacontad, ... hecatontad, chiliad, myriadMyriadMyriad , "numberlesscountless, infinite", is a classical Greek word for the number 10,000. In modern English, the word refers to an unspecified large quantity.-History and usage:...