Search Result for "entasis": 
Wordnet 3.0

NOUN (1)

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



The Collaborative International Dictionary of English v.0.48:

Entasis \En"ta*sis\, n. [NL., from Gr. ? a stretching; fr. ?; ?
   in + ? to extend.]
   1. (Arch.) A slight convex swelling of the shaft of a column.
      [1913 Webster]

   2. (Med.) Same as Entasia.
      [1913 Webster]


WordNet (r) 3.0 (2006):

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