homophone: two words are homophones if they are pronounced the same way but differ in meaning or spelling or both (e.g. bare and bear)
homonym: two words are homonyms if they are pronounced or spelled the same way but have different meanings
worm: 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