boo 

1. a thing u can yell to scare someone...
(although you probably wanna hide behind a corner then jump out cause they wont expect that)
2. The ghost thing off the mario brothers game... you know
3. a significant other... guys usually say it to there girls
4. boo as in you are really bad and you should stop what your doing right now... or ill throw rotten food at u...

1. person 1: Boo!!
person 2: ahh!! aw its only you, you scared the hell out of me man.. dont do that again.

2. boo as in the ghost...

3. girl u know your my boo

4. Boo, get off the stage you suck...

boo by Melissa_0049 December 24, 2006

boo 

a term used in prison referring to someone as your bitch but the term has been taken out by the black man to the urban streets as your loved one

black man- "yea thats right mother fucker you take it cuz you always gonna be my boo"

boo by nick zanko August 15, 2006

boo 

The acronym of the band Born of Osiris.

"hey dude i heard boo was on summer slaughter tour"

"yeah its gunna be sick"

boo by KaseyKocaine September 28, 2008

Boo 

A cute way to express displeasure, or sympathetic feelings.

A shortened version of boo urns.

Person 1: "I don't want to go to work today"
Person 2: "Boo, work!"

Person 1: "My sister's kitten is sick"
Person 2: "Boo, sick kitty!"

Boo by Naughtybat September 11, 2008

Boo 

what people say on bebo which really doesnt scare anyone.

1st person: BOO!
2nd person: Ahh u scared me *coughcough*

Boo by Yazmin1010 April 10, 2008

Boo 

A name for someone who is always there for you, and who unconditionally loves you.

Usually used for a boyfriend/girlfriend, but is also used for someone you love and is significant in your life.

I love you boo.

Boo by MakeYouSmile May 29, 2010

Boo 

The most amazin thing to ever walk this earth, you see her and your jaw is instantly broke cause it hits the floor so damn hard!! She's my everythin and wooahhh I aint never gonna let her go :)

Boo you are so fit :)

Boo by Roo July 20, 2004