Source : Webster's Revised Unabridged Dictionary (1913)

Calyx \Ca"lyx\, n.; pl. E. {Calyxes}, L. {Calyces}. [L. calyx,
   -ycis, fr. Gr. ? husk, shell, calyx, from the root of ? to
   cover, conceal. Cf. {Chalice Helmet}.]
   1. (Bot.) The covering of a flower. See {Flower}.

   Note: The calyx is usually green and foliaceous, but becomes
         delicate and petaloid in such flowers as the anemone
         and the four-o'clock. Each leaf of the calyx is called
         a sepal.

   2. (Anat.) A cuplike division of the pelvis of the kidney,
      which surrounds one or more of the renal papill[ae].

Source : WordNet®

calyces
     See {calyx}

calyx
     n : (botany) the whorl of sepals of a flower collectively
         forming the outer floral envelope or layer of the
         perianth enclosing and supporting the developing bud;
         usually green
     [also: {calyces} (pl)]