Listlessness and dissatisfaction resulting from lack of interest; boredom: "The servants relieved their ennui with gambling and gossip about their masters” ( John Barth). (noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "ennui" in a sentence
"Prior to this we'd had limited access to the French word "ennui" - a more grandiose, long-term boredom - but once we had our own word for listless dissatisfaction, we embraced it."
"So, I suppose, this ennui is the ying to that yang."
""I suppose this is what they call ennui," said Eric again, after a pause."