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[boo] /bu/
(used to express contempt or disapprobation or to startle or frighten).
noun, plural boos.
an exclamation of contempt or disapproval:
a loud boo from the bleachers.
verb (used without object), booed, booing.
to cry boo in derision.
verb (used with object), booed, booing.
to show disapproval of by booing.
Origin of boo1
First recorded in 1810-20; expressive formation


[boo, boh] /bu, boʊ/
Slang. marijuana.
Also called boo grass.
First recorded in 1955-60; of uncertain origin


[boo] /bu/
noun, Slang.
one's boyfriend or girlfriend.
1985-90; possibly an alteration of French beau boyfriend, admirer Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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Examples from the Web for boo
Contemporary Examples
Historical Examples
  • And you look now as if somebody's ghost had riz and hollered 'boo!'

    Cy Whittaker's Place Joseph C. Lincoln
  • He dashed up noisily from the underbrush, swung his arms, and shouted, “boo!”

    The Boy Settlers

    Noah Brooks
  • Our sleigh tumbled on one side or the other, upsetting before we could say "boo!"

    The Land of the Long Night Paul du Chaillu
  • In the daytime she has a weakness for picture hats, and she can't say boo to a goose.'

    The Explorer W. Somerset Maugham
  • But this time Miss Wayne never said 'boo,' when I couldn't hold in any longer.

    Heart of Gold

    Ruth Alberta Brown
British Dictionary definitions for boo


an exclamation uttered to startle or surprise someone, esp a child
a shout uttered to express disgust, dissatisfaction, or contempt, esp at a theatrical production, political meeting, etc
would not say boo to a goose, is extremely timid or diffident
verb boos, booing, booed
to shout "boo" at (someone or something), esp as an expression of disgust, dissatisfaction, or disapproval: to boo the actors
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for boo

expression meant to startle, early 15c., boh, "A combination of consonant and vowel especially fitted to produce a loud and startling sound" [OED, which compares Latin boare, Greek boaein "to cry aloud, roar, shout."]; as an expression of disapproval, 1801 (n.), 1816 (v.); hence, the verb meaning "shower someone with boos" (1893).

Booing was common late 19c. among London theater audiences and at British political events; In Italy, Parma opera-goers were notorious boo-birds, but the custom seems to have been little-known in America till c.1910.

To say boo "open one's mouth, speak," originally was to say boo to a goose.

To be able to say Bo! to a goose is to be not quite destitute of courage, to have an inkling of spirit, and was probably in the first instance used of children. A little boy who comes across some geese suddenly will find himself hissed at immediately, and a great demonstration of defiance made by them, but if he can pluck up heart to cry 'bo!' loudly and advance upon them, they will retire defeated. The word 'bo' is clearly selected for the sake of the explosiveness of its first letter and the openness and loudness of its vowel. [Walter W. Skeat, "Cry Bo to a Goose, "Notes and Queries," 4th series vi Sept. 10, 1870]

Online Etymology Dictionary, © 2010 Douglas Harper
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Slang definitions & phrases for boo

boo 1


Excellent; remarkable: Something that used to be known as the cat's whiskers is now called ''deadly boo'' (1950s+)


Marijuana or another narcotic: I got over there and she lays this dynamite boo on me, I mean super shit (1930s+ Jazz musicians)

Related Terms


[noun sense said to be fr black English jabooby, ''marijuana, so called because it induces a state of fear or anxiety,'' of unknown origin; but possibly fr Budda, ''marijuana'']

boo 2


  1. An exclamation of disapproval, the equivalent of a hiss (1890s+)
  2. A supposedly frightening exclamation, such as a ghost might give: She jumped out of the closet and hollered ''Boo!'' (1940s+)


: Next time at bat he was roundly booed

The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D.
Copyright (C) 2007 by HarperCollins Publishers.
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