Nauseous or nauseated?
Nauseous: adjective - sick, nauseated; offensive to taste or smell; loathsome, disgusting, repulsive.
Nauseate: verb - become affected with nausea, feel disgusted or sick; reject food with loathing; loathe or abhor; cause nausea or aversion, create loathing.
Basically; if you’re feeling ‘nauseous’ (adjective), you’re feeling sick. However, if some substance or event is ‘nauseous’, it is something that causes sickness and disgust.
To be nauseated (verb) is to feel sick, to be affected by disgust or loathing. However, if YOU cause the disgust, etc., you are being nauseating; i.e. you are the cause of the sickness or aversion of others.
As is so often the case in English, the distinction is nice and therefore not always readily seen.
‘The pervading stink of raw sewage following the flooding caused many people to feel nauseous.’ (adjective)
‘Fred was nauseated by the reports of child molestation amongst the Catholic clergy.’ (verb)
‘For much of the crossing, Johnson was nauseated; his sea-sickness lasting until the vessel docked in calm waters.’ (verb)
Pic: Across the Bay to Bridlington, East Yorkshire.