# boo

> English word · Interjection · IPA /buː/ · frequency rank #8,014

## Definitions
1. A loud exclamation intended to scare someone. Usually used when one has been hidden from the target, and then appears unexpectedly.
2. An exclamation used by a member of an audience, as at a stage play or sporting event, to indicate derision or disapproval.

## Etymology
From earlier (15c.) boh, coined to create a loud and startling sound. Compare Middle English bus! (“bang!”, interjection), Latin boō (“cry aloud, roar, shout”, verb), Ancient Greek βοάω (boáō, “shout”, verb).

## Easily confused with
- **by** (https://plainspell.com/en/vs/boo-vs-by)
- **BS** (https://plainspell.com/en/vs/boo-vs-bs)
- **br** (https://plainspell.com/en/vs/boo-vs-br)
- **Bt** (https://plainspell.com/en/vs/boo-vs-bt)
- **BP** (https://plainspell.com/en/vs/boo-vs-bp)
- **BW** (https://plainspell.com/en/vs/boo-vs-bw)
- **BX** (https://plainspell.com/en/vs/boo-vs-bx)
- **but** (https://plainspell.com/en/vs/boo-vs-but)
- **buy** (https://plainspell.com/en/vs/boo-vs-buy)
- **boy** (https://plainspell.com/en/vs/boo-vs-boy)
- **box** (https://plainspell.com/en/vs/boo-vs-box)
- **bus** (https://plainspell.com/en/vs/boo-vs-bus)
- **bro** (https://plainspell.com/en/vs/boo-vs-bro)
- **bye** (https://plainspell.com/en/vs/boo-vs-bye)
- **bow** (https://plainspell.com/en/vs/boo-vs-bow)
- **bug** (https://plainspell.com/en/vs/boo-vs-bug)
- **bud** (https://plainspell.com/en/vs/boo-vs-bud)
- **BTW** (https://plainspell.com/en/vs/boo-vs-btw)
- **bra** (https://plainspell.com/en/vs/boo-vs-bra)
- **bot** (https://plainspell.com/en/vs/boo-vs-bot)

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/boo