boo 

1. a jeer used by the audience at a performace, game, etc, to show disapproval

2. to utter the jeer mentioned above

3. marijuana

4. a supposedly frightening exclamation such as a ghost might say

When he failed to get a home run, the audience booed him.

boo by Light Joker May 28, 2006

boo 

affectionate name for your girlfriend/boyfriend

used in that old Usher song, My Boo

'you will always be my boo'

i love my boo, he's da sweetest ^___^

boo by heavily/endowed. January 16, 2008

boo 

An exclamation yelled at the top of one's lungs while running through the house, arms flailing, air-drying your wet, naked body.

Natdrea, "Are you almost done in the shower, Phil?"
Running through the house naked, Phil, "Booooooooooooooooooooooo oooooooooooooooooooooooo ooooooooooooooooooooo ooooooooooooooooooooooooooooooooooo oooooooooooooooo ooooooooooooooooooo oooooooooo!!!!!!!!! !!!!!!!"
Natdrea, "Sounds like the shower is free"

boo by Natdrea August 15, 2007

Boo 

A Boo is a small, fluffy round pink or white cloud-like creature. They are special unique things. They are usually quite almighty creatures and hold many powers. Special Boos have tiny wings and halos, representing and guarding the other not-so-special Boos. One thing about Boos, is they absolutely love Bears.

Boo: I love you, Bear
Bear: I love you, Boo.

Boo by Holleh December 28, 2005

Boo 

Never ever gonna get butt love. Not even if there's a fire.

You: Hey how bout some bf later?

Me: booooo

Never gonna have it.

Boo by Beefy one September 28, 2013

boo 

Boyfriend of girlfriend

Sup boo, wanna bounce to mah cribk so I could get sum hardcore

boo by Brittany April 21, 2004

Boo 

A man or womans lover, child or friend.

What's up Boo.

Boo by M O Thomas October 20, 2008