To slither means to move by sliding smoothly along the ground with a twisting, gliding motion, the way a snake moves across sand or through grass. A snake has no legs, so it pushes its body in S-shaped curves, each muscle working in sequence to propel it forward. Watch a snake closely and you'll see it gripping tiny bumps in the ground with its scales, creating a rippling motion that looks almost like water flowing.

The word captures both the movement and the feeling it creates. When something slithers, there's often something unsettling or sneaky about it. A lizard might slither under a rock. In stories, villains might slither through shadows. You might say someone slithered out of a room if they left quietly and sneakily, trying not to be noticed.

Other creatures slither too: eels slither through water, worms slither through soil after rain, and even some caterpillars slither along branches. The movement is always smooth and close to the ground, and it can be a bit eerie to watch. If you see something slithering toward you in tall grass, your first instinct is probably to jump back, even before you know what it is.