Prudishness is the quality of being too easily shocked by sex, by bodies, or by plain talk about either. The word is not kind. When you name someone’s prudishness, you are saying the shock is too big for the thing itself — a kiss, a love scene, a health lesson, a normal word for the body is treated as if it were dirty. It is the noun that belongs with the adjective prudish: you talk about her prudishness, or the prudishness of a rule, a school, a whole time in history. Writers also say prudery for much the same habit. Prudishness feels a little more like “the state of being prudish”; prudery a little more like “that stiff culture.” Both belong in books, reviews, and careful talk, not in the playground. Friends just say “Don’t be like that.” Though actually, wanting a quiet room, or not wanting a sex joke in front of children, is not automatically this. The sting is for when the shock looks larger than the moment. And it has nothing to do with prudence, which is careful good sense about risk.

假正經（名詞，指那種態度；貶義）