(n) an animal that walks with the entire sole of the foot touching the ground as e.g. bears and human beings, Syn. plantigrade, Ant. digitigrade mammal
The Collaborative International Dictionary of English (GCIDE) v.0.53 Collaborative International Dictionary (GCIDE)
a. [ L. planta sole of the foot + gradi to walk: cf. F. plantigrade. ] (Zool.) (a) Walking on the sole of the foot; pertaining to the plantigrades. (b) Having the foot so formed that the heel touches the ground when the leg is upright. [ 1913 Webster ]