Q From John David Hamilton: For many years I have been irritated by the misuse of the word nauseous which is all too often used when the user means nauseated. I was taught that when one is sick one feels nauseated but is often nauseous to others. I first heard this used by well-off but poorly educated New Yorkers but it has spread everywhere. Can you explain please and tell me whether nauseous in its newly offensive use is acceptable?
A There has been a lot of discussion about this in recent decades, and many American dictionaries flag the disputed senses in usage notes. As you say, the distinction that has been taught is that nauseous means “causing nausea” but nauseated means “feeling or suffering from nausea”. So if a person says “I am nauseous”, a purist might reply “Yes, you are; misusing words like that makes your listeners feel sick”. (This comment is best relayed from a distance.)
What seems to have happened in the US is that a new usage grew up some time before World War II — one writer suggests that it may have arisen first in the Bronx or Brooklyn, so your geographical sense is spot on — in which nauseous meant the same as nauseated: sick to the stomach. It was only as a result of this local usage that grammarians and usage guide writers after World War II seem to have begun to make a distinction between the two terms, one that some commentators point out is not altogether supported by word history. The Oxford English Dictionary has seventeenth-century examples of nauseous in the sense “inclined to nausea”, though in its entry — written in the late nineteenth century — it marks the sense as both rare and obsolete.
That entry will definitely be revised when the new edition comes out, since nauseous has now regained this meaning, a change that has been widely noted and commented on. Merriam-Webster’s Dictionary of English Usage says firmly: “Any handbook that tells you that nauseous cannot mean ‘nauseated’ is out of touch with the contemporary language. In current usage it seldom means anything else”. The new edition of the American Heritage Dictionary concurs: “Since there is a lot of evidence to show that nauseous is widely used to mean ‘feeling sick,’ it appears that people use nauseous mainly in the sense in which it is considered incorrect”.
But, as MDEU points out, there is subtlety in the way it is used. When nauseous means “feeling physically sick”, it usually appears after a verb such as feel, become, get or grow: “Doctor, I’m feeling nauseous”. When it means “causing nausea”, it is much more likely to be used before a noun: “To conceal the nauseous flavour of the raw spirit they added aromatic herbs and spices”. Much of the older sense of nauseous, both literal and figurative, is in the process of being transferred to nauseating: “To this, with nauseating smarminess, he immediately attested”, “The children looked a little green from the nauseating fairground rides”. Nauseated, to judge from the citation evidence, now seems to be less common than either.
It’s an interesting example of the way in which the language can change within a generation or so. It can only be annoying (nauseating, even) for somebody who has painfully learned a distinction between words to find that usage has changed and their knowledge is out of date. Think of it as language evolution in action.