1. Satisfied with the current situation and unconcerned with changing it, often to the point of smugness: "a geologic cautionary tale for a complacent world accustomed to reliable infusions of cheap energy" (Paul Roberts).
2. Eager to please; complaisant.
[Latin complacēns, complacent-, present participle of complacēre, to please : com-, intensive pref.; see COM- + placēre, to please; see plāk-1 in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.