Definition of complacency
1 : self-satisfaction especially when accompanied by unawareness of actual dangers or deficiencies When it comes to safety, complacency can be dangerous.
2 : an instance of usually unaware or uninformed self-satisfaction
Love words? Need even more definitions?Merriam-Webster unabridged
Words at Play
You're (Probably) Saying It Wrong
18 words even you might be mispronouncing
Great Big List of Beautiful & Useless Words
Along with their degrees of usefulness
What's the Difference?
These words shouldn't be used interchangeably
Words For Things You Didn't Know Have Names
When 'thingamajig' and 'thingamabob' just won't do
Ask the Editors