nauseous adj.

early 15c., "vomiting," from Latin nausea "seasickness," from Ionic Greek nausia (Attic nautia) "seasickness, nausea, disgust," literally "ship-sickness," from naus "ship" (from PIE root *nau- "boat"). Despite its etymology, the word in English seems never to have been restricted to seasickness. The 16c. canting slang had nase, or nasy "hopelessly drunk."

word-forming element making adjectives from nouns, meaning "having, full of, having to do with, doing, inclined to," from Old French -ous, -eux, from Latin -osus (compare -ose (1)). In chemistry, "having a lower valence than forms expressed in -ic."

1630s, "to feel sick, to become affected with nausea" (intrans.), 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), also figurative, "to loathe, to reject with disgust." Meaning "to create a loathing in, to cause nausea" is from 1650s. Careful writers use nauseated for "sick at the stomach" and reserve nauseous (q.v.) for "sickening to contemplate."