Source : Webster's Revised Unabridged Dictionary (1913)

Pisiform \Pi"si*form\, a. [L. pisum a pea + -form: cf. F.
   pisiforme.]
   Resembling a pea or peas in size and shape; as, a pisiform
   iron ore.

Pisiform \Pi"si*form\, n. (Anat.)
   A small bone on the ulnar side of the carpus in man and many
   mammals. See Illust. of {Artiodactyla}.

Source : WordNet®

pisiform
     n : a small wrist bone that articulates only with the triquetral
         [syn: {pisiform bone}, {os pisiforme}]