[n] any of numerous relatively small elongated soft-bodied animals especially of the phyla Annelida and Chaetognatha and Nematoda and Nemertea and Platyhelminthes; also many insect larvae
[n] screw thread on a gear with the teeth of a worm wheel or rack
[n] has a nasty or unethical character undeserving of respect
[v] to move in a twisting or contorted motion, (esp. when struggling); "The prisoner writhed in discomfort."; "The child tried to wriggle free from his aunt's embrace."
[v] move with slow, sinuous movements