What does entasis mean?
Entasis is the deliberate convex swell given to the shaft of a column so that its outline curves gently outward before tapering toward the top. The device was perfected by ancient Greek builders, who observed that a column cut along perfectly straight lines appears to sag or pinch inward when seen against the sky — an optical illusion. By adding a subtle bulge, they made the column seem straighter, stronger, and more alive to the eye. Entasis remains a touchstone of classical architecture: the columns of the Parthenon are among its most celebrated examples, though Roman, Renaissance, and even modern designers have employed it as well. The word is technical, belonging chiefly to architectural history and criticism, yet it captures a striking idea — that beauty sometimes requires a carefully measured imperfection. It serves as a reminder that what reads as 'straight' to the human eye may demand curvature behind the scenes.
nounA slight convex swelling or bulge given to a column or other vertical structure, so that its profile tapers gradually rather than following a perfectly straight line. In architecture, it is used to correct an optical illusion that makes untapered columns appear concave.
- The slight convex curvature built into the shaft of a column to correct the optical illusion that makes straight-sided columns appear concave.
"The Parthenon's columns owe their graceful strength in part to the subtle entasis worked into their tapering profiles."
"Classical Greek architects applied entasis so their columns would look straight and vigorous rather than pinched at the middle."
"Modern architects sometimes revive entasis digitally, using computer models to fine-tune the swelling of a tower's facade."
The plural 'entases' exists technically but is rare; the word is usually treated as uncountable when discussing the concept in general.
"The survey recorded subtle differences between the entases of the temple's outer and inner colonnades."
The Greeks knew a straight column looks weak — so they bent it on purpose, and called the fix 'entasis.'
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of entasis
Entasis derives from the Greek 'entasis,' meaning 'a stretching' or 'tension,' formed from 'enteinein,' 'to stretch tight,' from the root 'ten-' meaning 'to stretch.' English borrowed the term in the late seventeenth or early eighteenth century, when writers on architecture sought Greek vocabulary for classical building practices. It shares its root with words such as 'stasis,' 'static,' and 'ecstasy.'
How entasis is actually used
Entasis is a technical term used almost exclusively in architectural history and classical design discourse. It is a mass noun with no plural in ordinary use; it appears mainly in scholarly writing and is rarely encountered in general conversation.
Easily confused with entasis
'Stasis' means a state of motionlessness or stagnation, whereas 'entasis' refers to the slight outward curve of a column's profile.