A dream arousing feelings of intense fear, horror, and distress.(noun)
An event or experience that is intensely distressing.(noun)
A demon or spirit once thought to plague sleeping people.(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 "nightmare" in a sentence
"To expect politicians to correct this nightmare is a fantasy."
"If MAC is not allowed to protest, it has threatened to turn the day into what it called a "nightmare.""
"It's also helpful to realize, say sleep researchers, that what you call a nightmare may or may not actually be one."