1. on all fours - Adverb
2. on all fours - Phrase
on hands and knees
Source: WordNeton all-fours
If I had sharp claws I'd get on all fours. And scratch your back for free. Ed Harcourt
A boy cannot begin playing ball too early. I might almost say that while he is still creeping on all fours he should have a bouncing rubber ball. Christy Mathewson
One feels like crawling on all fours after reading your work. Voltaire
he got down on all fours to play with his grandson Source: Internet
As with otariids, it can turn its rear flippers forward and move on all fours; however, its swimming technique is more like that of true seals, relying less on flippers and more on sinuous whole body movements. Source: Internet
Apparently unaware of Sabine’s presence, the man kneeled down onto the packed snow and came on all fours, then—to Sabine’s profound surprise—began to crawl slowly onto the frozen river. Source: Internet