worm gear vs worm

worm gear and worm both are nouns.

Word	Noun	Adjective	Verb	Adverb
worm gear	Yes	No	No	No
worm	Yes	No	Yes	No

worm gear (noun)	worm (noun)
gear consisting of a shaft with screw thread (the worm) that meshes with a toothed wheel (the worm wheel); changes the direction of the axis of rotary motion	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
	screw thread on a gear with the teeth of a worm wheel or rack
	a software program capable of reproducing itself that can spread from one computer to the next over a network
	a person who has a nasty or unethical character undeserving of respect

worm gear (verb)	worm (verb)
	to move in a twisting or contorted motion, (especially when struggling)