cavetto

from WordNet (r) 3.0 (2006)

cavetto
    n 1: a concave molding shaped like a quarter circle in cross
         section

from The Collaborative International Dictionary of English v.0.48

Cavetto \Ca*vet"to\ (k[.a]*v[e^]t"t[-o]), n. [It. cavetto, fr.
   cavo hollow, L. cavus.] (Arch.)
   A concave molding; -- used chiefly in classical architecture.
   See Illust. of {Column}.
   [1913 Webster] Caviar