Source : Webster's Revised Unabridged Dictionary (1913)

Metacarpus \Met`a*car"pus\, n. [NL., fr. Gr. ?; ? beyond,
   between + ? the wrist.] (Anat.)
   That part of the skeleton of the hand or forefoot between the
   carpus and phalanges. In man it consists of five bones. See
   Illust. of {Artiodactyla}.

Source : WordNet®

metacarpus
     n : the part of the hand between the carpus and phalanges
     [also: {metacarpi} (pl)]