ennui

a feeling of listlessness and dissatisfaction arising from a lack of occupation or excitement.
ORIGIN mid 18th cent.: French, from Latin mihi in odio est ‘it is hateful to me.’ Compare with annoy .

Thesaurus
ennui
noun
an ennui bred of long familiarity boredom, tedium, listlessness, lethargy, lassitude, languor, weariness, enervation; malaise, dissatisfaction, melancholy, depression, world-weariness, Weltschmerz.