Noun. 1. homonym-two words are homonyms if they are pronounced or spelled the same way but have different meanings. word-a unit of language that native speakers can identify; words are the blocks from which sentences are made; he hardly said ten words all morning.om`o•nym′ic, adj. syn: homonym, homophone, and homograph designate words that are identical to other words in spelling or pronunciation, or both, while differing from them in meaning and usu. in origin. homophones are words that sound alike, whether or not they are spelled differently.