1630s, "to feel sick, to become affected with nausea," from nauseat- past participle stem of Latin nauseare "to feel seasick, to vomit," also "to cause disgust," from nausea (see nausea). Related: Nauseated; nauseating; nauseatingly. In its early life it also had transitive senses of "to reject (food, etc.) with a feeling of nausea" (1640s) and "to create a loathing in, to cause nausea" (1650s). Careful writers use nauseated for "sick at the stomach" and reserve nauseous (q.v.) for "sickening to contemplate."