A listless dissatisfaction, boredom with a faint taste of melancholy. The world has gone thin and effort no longer pays. Ennui is fatigue of the soul, not merely a lack of entertainment.

Borrowed from French ennui “boredom, vexation,” from Old French enoi “annoyance,” related to a sense of being troubled or burdened. The word’s elegance is deceptive: its roots are not languid but irritated.