entasis

American  

[en-tuh-sis] / ˈɛn tə sɪs /

noun

Architecture.

1. a slight convexity given to a column or tower, as to correct an optical illusion.

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entasis British  

/ ˈɛntəsɪs /

noun

1. a slightly convex curve given to the shaft of a column, pier, or similar structure, to correct the illusion of concavity produced by a straight shaft

2. Also called: entasia.  physiol an involuntary or spasmodic muscular contraction

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Etymology

Origin of entasis

1745–55; < Greek, equivalent to enta- (variant stem of enteínein to stretch tight, equivalent to en- en- ² + teínein to stretch) + -sis -sis

Example Sentences

The ancient Greeks made their columns bulge out slightly about a third of the way up to correct for the optical illusion of concavity — a technique known as entasis.

From Washington Post

This outward curvature of the profile is termed an entasis and in the Parthenon column, which is thirty-four feet in height, amounted to about three-fourths of an inch.

From Project Gutenberg

The entasis is almost invariably introduced in the spires of English churches.

From Project Gutenberg

The columns diminished at the top to about one-fifth of the lower diameter, and would seem to have had an entasis, as the lower portion up to one-third of the height is nearly vertical.

From Project Gutenberg

The columns, which are of Curzola marble, belong to the earlier building, though the entasis shows that classical feeling was beginning to affect even architects who worked in Gothic.

From Project Gutenberg