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

Where the spire has no entasis the same effect is produced by the introduction of small projecting gables, bands of carving, or a little coronal of pinnacles.

From Our Homeland Churches and How to Study Them by Heath, Sidney

This peculiarity is a convexity, or entasis, as it is called, on the inner faces.

From Roman Mosaics Or, Studies in Rome and Its Neighbourhood by Macmillan, Hugh

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

From Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 6 "English Language" to "Epsom Salts" by Various

The entasis from the temple of Mars Ultor in Rome compared with Vignola's rule for entasis.

From The Ten Books on Architecture by Vitruvius Pollio