Source : Webster's Revised Unabridged Dictionary (1913)

Ovolo \O"vo*lo\, n. [It. ovolo, uovolo, fr. L. ovum an egg. Cf.
   {Ovule}.] (Arch.)
   A round, convex molding. See Illust. of {Column}.

   Note: In Roman work it is usually a quarter circle in
         section; in Greek work it is flatter, and is equivalent
         to the echinus; that is, it has in section the elastic
         curve of the shell of the sea urchin. In medi[ae]val
         architecture it is not distinguishable from the
         multitude of convex moldings, of all sections, which
         are used.

Source : WordNet®

ovolo
     n : a convex molding having a cross section in the form of a
         quarter of a circle or of an ellipse [syn: {thumb}, {quarter
         round}]
     [also: {ovoli} (pl)]