Definitions by Larr

boo 

1) Boyfriend or girlfriend. Term of endearment.

2) A loud, abrupt yell, meant to frighten someone.

3) A sound made to indicate disapproval, the opposite of "yay."

1- Some Guy: "Hey boo."

2- Ghost: "BOOO!"

3- Unhappy Audience: "Booooooo...."

boo by Larr February 14, 2008