All′ fours″ [formerly, All four.] All four legs of a quadruped; or the two legs and two arms of a person.
To be, go, orrun, on all fours (Fig.), to be on the same footing; to correspond (with) exactly; to be alike in all the circumstances to be considered. “This example is on all fours with the other.” “No simile can go on all fours.” Macaulay.