plural boos
1
: a sound that people make to show they do not like or approve of someone or something
A chorus of boos was heard after the shot missed the goal.
The announcement was greeted by/with a mixture of boos and cheers.
2
informal
: any sound at all
—usually used in negative statements
He never said boo [=he never said anything], so I didn't even know he was there.
Note: A person who (US) wouldn't say boo or (Brit) wouldn't say boo to a goose is very quiet and shy.
1
—used to show dislike or disapproval of someone or something
The crowd shouted "Boo!" when the announcement was made.
Boo! Get off the stage.
Note: When people say "Boo!" with this meaning, they say it very slowly.
2
—used when a person frightens someone
My brother scared me when he jumped out from behind the door and shouted "Boo!"
Note: When people say "Boo!" with this meaning, they say it very quickly.
boos; booed; booing
: to show dislike or disapproval of someone or something by shouting "Boo" slowly
Many people in the crowd booed when the announcement was made.
Many people in the crowd booed the announcement, but a few people cheered it.
The crowd booed the singer off the stage. [=the crowd booed so much that the singer stopped singing and left the stage]
Cite this Entry
“Boo.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/boo. Accessed 16 Jun. 2026.
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