ennui (òn-wê´, òn´wê) noun

Listlessness and dissatisfaction resulting from lack of interest; boredom;

[French, from Old French enui, from ennuier, to annoy, bore, from Vulgar Latin *inodiâre, from Latin in odio (esse), (to be) odious : in, in. See in-2 + odio, ablative of odium, hate.]