Quantcast
Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Medical
  • Scrabble
  • Spanish Central
  • Learner's Dictionary

Medical Dictionary

black out

play
verb \(ˈ)blak-ˈau̇t\

Medical Definition of black out

  1. :  to undergo a temporary loss of vision, consciousness, or memory (as from temporary impairment of cerebral circulation, retinal anoxia, a traumatic emotional blow, or an alcoholic binge)—compare gray out, red out

  2. transitive verb

  3. :  to cause to black out




Learn More about black out


Seen and Heard

What made you want to look up black out? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

marked by propriety and good taste

Get Word of the Day daily email!

WORD GAMES

Take a 3-minute break and test your skills!

image567572573

Which of these is a synonym of unctuous?

angry maudlin prompt oily
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ