ENNUI
boredom, ennui, tedium
(noun) the feeling of being bored by something tedious
Source: WordNet® 3.1
Etymology
Noun
ennui (countable and uncountable, plural ennuis)
A gripping listlessness or melancholia caused by boredom; depression.
Synonyms
• acedia
• weltschmerz
• boredom
Verb
ennui (third-person singular simple present ennuis, present participle ennuying, simple past and past participle ennuyed or ennuied)
(transitive) To make bored or listless; to weary.
Source: Wiktionary
En`nui", n. Etym: [F., fr. L. in odio in hatred. See Annoy.]
Definition: A feeling of weariness and disgust; dullness and languor of
spirits, arising from satiety or want of interest; tedium. T. Gray.
Source: Webster’s Unabridged Dictionary 1913 Edition