A nicety means a small, fine detail or subtle distinction that might be easy to overlook. When your teacher explains the niceties of grammar, she's pointing out precise rules about comma placement or verb tenses that make your writing more correct and sophisticated. When a chef attends to the niceties of presentation, he carefully arranges each element on the plate.

The word often appears in the phrase “the niceties of,” followed by whatever subject has these fine points: the niceties of etiquette, the niceties of chess strategy, or the niceties of scientific procedure. These are the refined details that separate someone who knows the basics from someone who truly masters something.

Niceties can also mean small courtesies or polite gestures. When someone says “we don't have time for niceties,” they mean skipping the usual polite greetings and getting straight to urgent business. During a fire drill, you wouldn't waste time with social niceties like “how was your weekend?” before evacuating.

The word suggests something refined and precise rather than essential. You could survive without knowing every nicety of table manners, but understanding these details shows care, skill, and respect for getting things exactly right.