From Wordnik.com:
ennui (on WEE) - noun - A painful or wearisome state of mind due to the want of any object of interest, or to enforced attention to something destitute of interest; the condition of being bored; tedium. … A gripping listlessness or melancholia caused by boredom. … from Old French enui, from ennuyer, to annoy, bore; see annoy.
From Wordnik.com: ennui (on WEE) - noun - A painful or wearisome state of mind due to the want of any object of interest, or to enforced attention to something destitute of interest; the condition of being bored; tedium. … A gripping listlessness or melancholia caused by boredom. … from Old French enui, from ennuyer, to annoy, bore; see annoy.