Slither/ˈslɪðər/ Definition 1 of 3Pro Tip 1/2Animal Movement Used to describe the silent and smooth way certain animals move, like reptiles or insects. The lizard slithered up the wall. Pro Tip 2/2Slow and Quiet Implies a slow, stealthy movement without making much noise, not quick or loud. She watched the cat slither behind the sofa.