Puritanism, in the sense you need here, means strict religious and moral attitudes — especially a tight, unfriendly view of pleasure and sex — and the word is used to show disapproval. With a capital P, Puritanism also names the real historical movement of the Puritans in England and America in the 1500s and 1600s. Newspapers often blur the two: they say puritanism when they mean a modern killjoy mood, not a church. The disapproving everyday use is the one to learn first; the history is the background, not a different spelling. It is heavier than “being a bit strict.” It suggests a whole moral climate that watches people, especially around the body.

清教主義；清教徒式的嚴格道德觀（帶貶義）