nauseous UK /ˈnɔːziːəs/US /ˈnɔʃəs/ adjective3 •Afflicted with nausea; sick.After he had scarcely eaten enough, he felt nauseous; but nausea ceased as soon as he stopped eating entirely, … — 1848 •Causing nausea; sickening or disgusting.[…] And flattery tipt with nauseous fleer, And guilty shame, and servile fear, Envy, and cruelty, and pride, Will in your tainted heart preside. — 1720 •(no longer used) Inclined to nausea; sickly, squeamish. formsmore nauseous · most nauseous