Dictionary

nightmare

noun night·mare \ˈnīt-ˌmer\

: a dream that frightens a sleeping person : a very bad dream

: a very bad or frightening experience or situation

Full Definition of NIGHTMARE

1
:  an evil spirit formerly thought to oppress people during sleep
2
:  a frightening dream that usually awakens the sleeper
3
:  something (as an experience, situation, or object) having the monstrous character of a nightmare or producing a feeling of anxiety or terror
nightmare adjective
night·mar·ish \-ˌmer-ish\ adjective
night·mar·ish·ly adverb
ADVERTISEMENT

Examples of NIGHTMARE

  1. Mommy, I had a really scary nightmare.
  2. The party was a complete nightmare.

Origin of NIGHTMARE

Middle English, from 1night + 1mare
First Known Use: 14th century
NIGHTMARISH Defined for Kids

nightmare

noun night·mare \ˈnīt-ˌmer\

Definition of NIGHTMARE for Kids

1
:  a frightening dream
2
:  a horrible experience
night·mar·ish \ˈnīt-ˌmer-ish\ adjective

Word History of NIGHTMARE

The -mare in nightmare comes from an Old English word for a kind of evil spirit. Such spirits were believed to bother people who were sleeping.
Medical Dictionary

nightmare

noun night·mare \ˈnīt-ˌma(ə)r, -ˌme(ə)r\

Medical Definition of NIGHTMARE

:  a frightening or distressing dream that usually awakens the sleeper

Browse

Next Word in the Dictionary: night monkeyPrevious Word in the Dictionary: nightmanAll Words Near: nightmare
How to use a word that (literally) drives some people nuts.
Test your vocab with our fun, fast game
Ailurophobia, and 9 other unusual fears