1. boo - Noun
2. boo - Verb
3. boo - Interjection
4. Boo - Proper noun
a cry or noise made to express displeasure or contempt
show displeasure, as after a performance or speech
Source: WordNetA boo is a lot louder than a cheer, if you have 10 people cheering and one person booing all you hear is the booing. Lance Armstrong
I don't enjoy the boo scare when you're watching a movie and then suddenly there's a big shark on the screen. The only thing they're doing is catching you off guard. Sergio Aragones
Boo was our neighbor. He gave us two soap dolls, a broken watch and chain, a pair of good-luck pennies, and our lives. Harper Lee
She can be anything, Boo told me, and this is what I remember most, her freckled face so solemn, as if she knew she was the first to tell me. And so can you. Sarah Dessen
The people sitting in the free theater seats are the first ones to boo. Chinese Proverb
Et is ken Ding sau schlimm, et is boo gut für. Waldeck Proverb