entasis Meaning, Definition & Usage

  1. noun a slight convexity in the shaft of a column; compensates for the illusion of concavity that viewers experience when the sides are perfectly straight

WordNet

En"ta*sis noun
Etymology
NL., from Gr. a stretching; fr. in + to extend.
Definitions
  1. (Arch.) A slight convex swelling of the shaft of a column.
  2. (Med.) Same as Entasia.

Webster 1913