nauseous(adjective) adjective1. causing or able to cause nausea- a nauseating smell- nauseous offalSimilar word(s): unwholesome, loathsome, nauseating, noisome, offensive, queasy, sickening, vile2. feeling nausea; feeling about to vomitSimilar word(s): ill, sick, nauseated, queasy, sick, sickish