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.