To cavil means to make petty or unnecessary objections about small, unimportant details. When someone cavils, they're finding fault with tiny things that don't really matter, often just to be difficult or show off how clever they think they are.

Imagine you've written a great book report. Instead of discussing your ideas, someone cavils about whether you used “big” or “large” in one sentence, or complains that your margins are slightly off. They're missing the whole point by obsessing over trivial details.

The word often appears in the phrase cavil at, as in “The food critic caviled at the restaurant's silverware placement but admitted the meal was delicious.” A person who cavils regularly is called a caviler, though you might also hear them called nitpicky or fussy.

Caviling is different from genuine criticism or careful editing. Good editors catch real problems that improve your work. Cavilers just waste everyone's time by complaining about things that don't affect quality or meaning. They're like someone who interrupts a fascinating story to correct whether something happened on Tuesday or Wednesday, when the day of the week doesn't matter to the story.