Ennui

l'ennui is a masculine noun that is pronounced "an - nui" and means either:
boredom:
mourir d'ennui! = to die of boredom
quel ennui! = what a bore!

problem, trouble:
il a des ennuis = he has problems
j'ai des ennuis avec la police = I'm in trouble with the police
il a des ennuis de santé = he has health problems