homonym (Noun). A word that both sounds and is spelled the same as another word but has a different meaning. homonym (Noun). A word that sounds or is spelled the same as another word but has a different meaning, technically called a homophone (same sound) or a homograph (same spelling).homonym (Noun). A name for a taxon that is identical in spelling to another name that belongs to a different taxon. word that sounds or is spelled the same as another word but has a different meaning, technically called a homophone (same sound) or a homograph (same spelling). homonym (Noun). A name for a taxon that is identical in spelling to another name that belongs to a different taxon.