black out
Idioms-
Obliterate with black, as in crossing out words on a page or print on a screen. For example, They have blacked out all the obscene words in the subtitles to make this movie suitable for youngsters . This usage may be derived from an earlier meaning, “to stain or defame,” which dates from the 15th century (and probably alludes to “blackening” a person's reputation). [Mid-1800s]
-
Extinguish all lights. For example, The whole town was asleep, as blacked out as London during the war . In the early 1900s this expression alluded to the lights in a theater, but from about 1940 on it meant darkening an entire city to hide it from enemy bombers.
-
Lose consciousness, faint; also, experience a temporary loss of memory. For example, I couldn't remember a single note of the music; I blacked out completely , or The accused man claims he blacked out after his first drink . This usage is thought to have originated with pilots, who sometimes fainted briefly when pulling out of a power dive. It soon was transferred to other losses of consciousness or memory. [c. 1940]
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
They allege the second black out occurred because the crew was relying on a flushing pump to supply fuel to two of the ship's generators.
From BBC ● May 12, 2026
“They can’t black out the whole country,” Kolisnyk said.
From The Wall Street Journal ● Dec. 24, 2025
I didn’t, of course, die or even black out.
From Los Angeles Times ● Sep. 13, 2024
Not because I black out and instantly transform into an immature child anytime a person starts talking about feces, but apples.
From Salon ● Apr. 11, 2024
Oh snap, you did another black out joint!
From "Booked" by Kwame Alexander
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
