from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun Marijuana.
  • noun A sound uttered to show contempt, scorn, or disapproval.
  • noun Informal Any sound or word.
  • interjection Used to express contempt, scorn, or disapproval or to frighten or surprise another.
  • intransitive verb To utter a boo.
  • intransitive verb To express contempt, scorn, or disapproval of by booing.

from The Century Dictionary.

  • Same as bo.
  • noun Same as bu.

from the GNU version of the Collaborative International Dictionary of English.

  • verb to show displeasure (after a performance or speech) by making a prolonged sound of “boo”.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • interjection A loud exclamation intended to scare someone, especially a child. Usually used when one has been hidden from the victim and then suddenly appeared unexpectedly.
  • interjection A word used ironically in a situation where one might have scared someone, but said someone was not scared. Not said as loudly as in definition 1.
  • interjection An exclamation used by a member or many members of an audience, as at a stage play or sports game, to indicate derision or disapproval of what has just occurred.
  • noun A derisive shout made to indicate disapproval.
  • noun US, slang A close acquaintance or significant other, derived from French beau.
  • verb intransitive To shout extended boos derisively.
  • verb transitive To derisively shout extended boos at.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun a cry or noise made to express displeasure or contempt
  • verb show displeasure, as after a performance or speech


from The American Heritage® Dictionary of the English Language, 4th Edition

[Origin unknown.]

from The American Heritage® Dictionary of the English Language, 4th Edition


from Wiktionary, Creative Commons Attribution/Share-Alike License

Coined to create a loud and startling sound. Compare Latin boō ("to cry aloud, roar, shout").


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  • Jane Smiley on ghosts.

    February 1, 2008

  • Supposedly derived from Boh, a general from Norse myth. Boh was a son of Odin and a general, and was so fierce and powerful that the mere mention of his name struck fear in the hearts of his enemies. Viking warriors would shout his name when launching a surprise attack, and that eventually led to the custom of shouting "Boo!" when surprising someone.

    January 13, 2009

  • I love my unicorn, he knows I am true,

    My troubles go poof, my unicorn named Boo.

    - Mariah Carey, The Unicorn

    January 14, 2009

  • Term of endearment.

    June 14, 2009

  • If someone calls you boo (as a term of endearment) have you been booed?

    June 14, 2009

  • my godmother's name is "Boo". ( my father gave her the name.) I have never given up on the ghost. c'est vrai.

    June 14, 2009

  • Another meaning for boo is boyfriend/girlfriend. From "My Boo" written by Jermaine Dupri, Manuel Seal, Jr., Adonis Shropshire, Alicia Keys, and Usher: "Know that you're that one for me/it's clear for everyone to see/Ooh baby, you will always be my boo"

    August 2, 2009

  • I remember the first time one of my dearest friends referred to me as “boo”. That had to be way back in the late 80’s early 90’s. Today everyone knows what boo means. It’s a term of endearment, it’s a way of letting someone know that you like them. For example if I run into you at the mall and I shout out “Hey Boo!” You know I’m saying, “ glad to see you, you’re looking good and I like you” and a bunch of other good stuff all wrapped up into one neat little 3-letter package – B-O-O!...Remember Mo’Nique when she was on the Parker’s? Whenever her character Nikki Parker saw Professor Stanley Oglevee she would say, “Hey Boo!”

    December 2, 2009

  • Code for Bodo Airport, Bodo, Norway.

    December 29, 2009