Webster's Revised Unabridged Dictionary · 1913

Plantigrade

Plantigrade , adjective

[Latin planta sole of the foot + gradi to walk: compare French plantigrade.]

(a)
(Zoology) Walking on the sole of the foot; pertaining to the plantigrades.
(b)
(Zoology) Having the foot so formed that the heel touches the ground when the leg is upright.

Plantigrade , noun

(Zoology) A plantigrade animal, or one that walks or steps on the sole of the foot, as man, and the bears.