In architecture

Architecture

Architecture is both the process and product of planning, designing and construction. Architectural works, in the material form of buildings, are often perceived as cultural and political symbols and as works of art...

, entasis is the application of a convex curve to a surface for aesthetic purposes. Its best-known use is in certain orders of Classical

Classical architecture

Classical architecture is a mode of architecture employing vocabulary derived in part from the Greek and Roman architecture of classical antiquity, enriched by classicizing architectural practice in Europe since the Renaissance...

 column

Column

A column or pillar in architecture and structural engineering is a vertical structural element that transmits, through compression, the weight of the structure above to other structural elements below. For the purpose of wind or earthquake engineering, columns may be designed to resist lateral forces...

s that curve slightly as their diameter is decreased from the bottom upwards. In the Hellenistic period some columns with entasis are cylindrical in their lower parts. Some Roman columns are 'cigar-shaped', with the widest point some distance above the foot, but this is unusual and to most eyes unattractive.

The word derives from the Greek word ἐντείνειν, to stretch tightly.
Probably the first use of entasis was in the construction of the Egypt

Egypt

Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...

ian pyramid

Egyptian pyramids

The Egyptian pyramids are ancient pyramid-shaped masonry structures located in Egypt.There are 138 pyramids discovered in Egypt as of 2008. Most were built as tombs for the country's Pharaohs and their consorts during the Old and Middle Kingdom periods.The earliest known Egyptian pyramids are found...

s, but it can also be observed in Classical period Greek

Architecture of Ancient Greece

The architecture of Ancient Greece is the architecture produced by the Greek-speaking people whose culture flourished on the Greek mainland and Peloponnesus, the Aegean Islands, and in colonies in Asia Minor and Italy for a period from about 900 BC until the 1st century AD, with the earliest...

 column designs, for example in the Doric-order

Doric order

The Doric order was one of the three orders or organizational systems of ancient Greek or classical architecture; the other two canonical orders were the Ionic and the Corinthian.-History:...

 temples in Segesta

Segesta

Segesta was the political center of the Elymian people, located in the northwestern part of Sicily, in what are now the province of Trapani and the comune of Calatafimi-Segesta....

, Selinus, Agrigento

Agrigento

Agrigento , is a city on the southern coast of Sicily, Italy, and capital of the province of Agrigento. It is renowned as the site of the ancient Greek city of Akragas , one of the leading cities of Magna Graecia during the golden...

 and Paestum

Paestum

Paestum is the classical Roman name of a major Graeco-Roman city in the Campania region of Italy. It is located in the north of Cilento, near the coast about 85 km SE of Naples in the province of Salerno, and belongs to the commune of Capaccio, officially also named...

.