1550s, "trim, neat, spruce, smart," possibly an alteration of Low German smuk "trim, neat," from Middle Low German smücken "to adorn" (originally "to dress," secondary sense of words meaning "to creep or slip into"), from the same source as smock. The meaning "having a self-satisfied air" is from 1701, an extension of the sense of "smooth, sleek" (1580s), which was commonly used of attractive women and girls. Related: Smugly; smugness.
例文
1. He tried hard not to smile in smug self-satisfaction.
彼は自慢の笑顔を強く我慢した。
2.Thomas and his wife looked at each other in smug satisfaction.
トーマスと夫人は得意げに見つめ合った。/
3.The programme seemed false and sugary,and the characters smug .