You may be thinking, don't you mean Complacent? That depends. Both words have a similar definition, but their meanings vary oh so slightly. Here's why.
Complaisant is an adjective, which means to to be obliging, willing or inclined to please, or to easily agree with others.
An employee may be Complaisant to his supervisor, hoping to get a promotion.
Complacent (also an adjective), on the other hand, means to be pleasant or pleased with oneself, their situation or advantages, often without knowing about an impending, potential danger or setback. It's almost like a "little did he know" word, in a sense.
Citizens of the United States were Complacent during WWII until the bombing of Pearl Harbor.
The Intern walked away with a Complacent smile, knowing that he nailed that interview.
Both words are pronounced the same with subtle differences. Be sure to choose wisely if you wish to use this word so that the right meaning is applied.