slither

Concise Oxford English Dictionary © 2008 Oxford University Press:
slither/ˈslɪðə(r)/

▶verb move smoothly over a surface with a twisting or oscillating motion.

■ slide or slip unsteadily on a loose or slippery surface.

▶noun

• 1 a slithering movement.

• 2 a sliver.

– derivatives
slithery adjective.

– origin ME: alt. of the dial. verb slidder, frequentative from the base of slide.