idle·ness noun (-es) Etymology: Middle English idelnesse (also, vanity) from Old English īdelnes, from īdel + -nes -ness : the quality or state of being idle (as through lack of worth, occupation, employment, industry) < the idleness of our search > < increasing idleness in the auto industry > < a person of unbelievable idleness > also: an instance of such idleness < our yesterday's idleness forgotten >