The Collaborative International Dictionary of English v.0.48:
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. [1913 Webster] MetacenterWordNet (r) 3.0 (2006):
metacarpus n 1: the part of the hand between the carpus and phalanges