boo

expression of dissapproval.

B. Gates: This is the all-great Windows XP.

Me: boo!

by vin July 22, 2004

boo

Sound that a fake ghost would make

Ghost:BOOOO!
Child:AHHHHHHH!

by BEYONCE November 8, 2003

boo

A word used to scare people.

Guy: "BOO!"
Guy2: "omgwtfbbq"

by Gracin July 29, 2005

boo

A word used to scare a person

Person 1: BOOOO!!!
Person 2: AHHH!!!

by Reagan Lausche February 21, 2005

boo

A guy steps on home plate.
The crowd doesn't like that guy.
They shout "BOO".

"Boo, you stink a lot you bad player."

by medium bro December 6, 2006

boo boo

1)when someone is an idiot

2)something has gone bad or is gone

josh: hey where did that bowl go?
brandon: right here bro, damn that shit is boo boo

by giantdick-O-tron June 20, 2011

boos

Boos is never given a concrete definition, only prefaced when its used with any context at any time, and may be used for both negative and positive reasons in the same sentence.

Person 1: i got the hookah.
Person 2: is it boos?
Person 1: its pretty boos.
---
Person 1: when you rollin in?
Person 2: tues night
Person 1: boos
---
Person 1: I'll be over in like 10 minutes.
Person 2: Boos.
--
Person 1: so hows phil
Person 2: Boos

by Geem-Unit July 16, 2008