ON ALL FOURS

adv. phr. 1. On all four legs; on hands and knees. Fido sat up to "beg" but dropped down on all fours to eat the dog biscuit Sam gave him. Billy's father got down on all fours and gave the baby a ride. 2. informal On a level of equality; of the same value. Wigs may be widely used, but they are still not on all fours with beautiful natural hair.