Ornithopoda

from The Century Dictionary.

• An order of Dinosauria, containing extinct herbivorous dinosaurs whose hind feet most nearly approached those of birds in structure and function.

from the GNU version of the Collaborative International Dictionary of English.

• proper noun plural (Paleon.) An order of herbivorous dinosaurs with birdlike characteristics in the skeleton, esp. in the pelvis and hind legs, which in some genera had only three functional toes, and supported the body in walking as in Iguanodon. See Illust. in Appendix.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun widespread group including duck-billed dinosaurs and their early relatives (hadrosaurs, trachodon and iguanodon)