DIGITIGRADE is a 11 letter word that starts with D.

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

2. \Dig"i*ti*grade\, n. (Zo["o]l.)
   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.