complacent / complaisant are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
complacent: (adjective) contented to a fault with oneself or one's actions.
complaisant: (adjective) showing a cheerful willingness to do favors for others.
complacent: k·ah·m·p·l·EY·s·ah·n·t
complaisant: k·ah·m·p·l·EY·s·ah·n·t
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)