23 Moby Thesaurus words for "bad breath": BO, bad smell, body odor, fetidity, fetidness, fetor, foul breath, foul odor, frowst, graveolence, halitosis, malodor, mephitis, miasma, nidor, noxious stench, offensive odor, reek, reeking, rotten smell, stench, stench of decay, stink