adj1. (Zoology) (of the feet of certain birds) specialized for walking2. (Zoology) (of birds, such as the ostrich) having such feet[C19: from New Latin gressōrius, from gressus having walked, from gradī to step]
gressorial
gressorial
[gre′sȯr·ē·əl] (vertebrate zoology) Adapted for walking, as certain birds' feet.