"Go on fours" is a phrase that means to move on hands and knees, staying low to the ground. Some synonyms for this phrase include crawling, creeping, or even slithering. These words are often used to describe the movements of animals or humans, such as babies crawling for the first time or a person trying to move quietly in a small space. The phrase can also suggest a sense of vulnerability or submission, as going on fours is often associated with being on the ground, at the mercy of predators or other dangers. Regardless, there is no shortage of ways to describe this particular type of movement.