Definition of "complacence" [com•pla•cence]

• Contented self-satisfaction. (noun)
• Total lack of concern. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "In her voice and complacence she, too, showed the drill-marks of order and restraint."
• "Later, irritated by his self-satisfied complacence and after listening to a recital of how he had cornered the Klamath salmon – packing, planted the first oysters on the bay and established that lucrative monopoly, and of how, after exhausting litigation and a campaign of years he had captured the water front of Williamsport and thereby won to control of the Lumber Combine, she returned to the charge."
• "If we're doing well, our over-confidence can devolve into complacence, thinking that our future will continue on the same trajectory as our past."