Have you ever used the excuse of staying home, saying, “I feel nauseous”?

You probably meant that you weren’t feeling well, and that is the way most people interpreted your words. It’s also possible that a well-meaning friend corrected you by saying, “I think you mean ‘nauseated.’”

Using the proper form of the word may not do anything to improve your health, but it might make all the difference in the world to how your resident grammar nerd feels.

The word “nauseous” has Greek and Latin origins. It is properly defined as “causing nausea.” In other words, anything that is so revolting in appearance, smell, taste, or other quality that it puts you in danger of throwing up is nauseous.

If you want to describe the condition of being afflicted with nausea, the word you are looking for is “nauseated.” It is the natural result of encountering something that is nauseous.

When you say, “I am nauseous,” your friendly neighborhood grammar nerd feels compelled to correct you. That’s because he or she interprets your words as, “Warning: I am so utterly revolting that if you come near me, I will make you puke your guts out.”

In The Elements of Style, William Strunk and E.B. White make this distinction: “[nauseous] means ‘sickening to contemplate’; [nauseated] means ‘sick at the stomach.’ Do not, therefore, say ‘I feel nauseous,’ unless you are sure you have that effect on others.”

If you don’t take well to having your words picked apart, you can always take comfort in the constantly-evolving nature of the English language. If a rule of grammar is broken by enough people, it tends to become optional. Decades of blurring the distinction between the two words have led dictionaries to acknowledge a secondary definition of “nauseous.” Webster’s dictionary gives “afflicted with nausea” as a secondary definition for “nauseous” and notes that anyone arguing against this interpretation is mistaken.

Of course, if you really want to be a purist about the whole thing, you should claim that the only time anyone experiences nausea is while suffering from seasickness. The word comes from the Greek “naus,” meaning “ship.”

Depending on how far you want to push the issue, your corrections may cause your associates to truly get sick of you, or you will drive grammar purists to get on a boat and sail away.