Complaisant or Complacent?

The homophones complaisant and complacent are often confused - and no wonder. Not only do they look and sound alike, but they also both derive ultimately from Latin complacēre, meaning "to please greatly." Complacent usually means "self-satisfied" or "unconcerned," but it also shares with complaisant the sense of "marked by an inclination to please or oblige." This sense of complacent is an old one, but that hasn't kept language critics from labeling it as an error - and on the whole, modern writers do prefer complaisant for this meaning. Conversely, complaisant is sometimes mistakenly used in contexts such as "complaisant about injustices," where complacent, with its sense of "marked by self-satisfaction especially when accompanied by unawareness of actual dangers or deficiencies," should go. One aid is to remember that with the preposition "about," you probably want complacent.