The Collaborative International Dictionary of English v.0.48:

Digitigrade \Dig"i*ti*grade\, a. [L. digitus finger, toe + gradi
   to step, walk: cf. F. digitigrade.] (Zool.)
   Walking on the toes; -- distinguished from plantigrade.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Digitigrade \Dig"i*ti*grade\, n. (Zool.)
   An animal that walks on its toes, as the cat, lion, wolf,
   etc.; -- distinguished from a plantigrade, which walks on the
   palm of the foot.
   [1913 Webster]

WordNet (r) 3.0 (2006):

digitigrade
    adj 1: (of mammals) walking on the toes with the posterior part
           of the foot raised (as cats, dogs, and horses do) [ant:
           plantigrade]
    n 1: an animal that walks so that only the toes touch the ground
         as e.g. dogs and cats and horses [syn: digitigrade
         mammal, digitigrade] [ant: plantigrade, plantigrade
         mammal]