Mach
WordNet
noun
(1) Austrian physicist and philosopher who introduced the Mach number and who founded logical positivism (1838-1916)
WiktionaryText
Noun
Mach
- a ratio of the speed (of an object, etc.) to the speed of sound in the fluid or other medium through which the object travels. Usually used to describe supersonic speeds.
- The jet traveled at Mach 3.
- the Mach number
Usage notes
- Never plural.
- Always precedes the number, as in the example above.