What does BOO mean??

You either say "Boo!" when you sneak up on someone and scare them; or you call that special someone in your life "boo". The latter is Black American slang and is a corruption of the French "beau".

One example of the latter is in the R&B hit "Dilema":

"...even when I'm with my boo
boy you know I'm crazy over you."

Another meaning according to Cambridge:

boo (DISAPPROVAL
verb [I or T] booing, booed, booed
to make an expression of strong disapproval or disagreement:

People at the back started booing loudly.
Her singing was so bad that she was booed off the stage

miguel
in my thesaurus boo means whisper, tease, make fun of

''boo'' is a Halloween word. ''boo'' is what a ghost says.

''boo'' is a curse word. Just kidding.

A cry or noise made to express displeasure or contempt

Yes, what you would shout while throwing tomatoes if you where in a theatre with a bad joker on the stage.

boooo

You guys are also missing another meaning of this slang.

It also refers to a 'silly mistake.'

Yesterday, I completed my whole project and handed it over to my boss but later I realized that I made a 'boo' not to mention my name at the front cover. Though he knows me very well coz I'm a wicked employee.

Boy,

In that case you committed a "boo boo." Generally the word is used twice to signify a mistake.

I look up the word ''boo'' in my dictionary and it only gave the definition of ,what a ghost says, or what you say to scare people. It didn't give any of the slang definition.

Here are all of the different examples I can think of:

1) The sound a ghost makes. Sometimes children will try to scare one another by jumping out of a closet and yelling "boo."

2) A sound made by an audience to show their displeasure.

"The crowd booed the unfunny comic."

3) "boo boo"......this is a slang term for a mistake.

4) An ebonics term for someone's romantic partner (usually a male talking about his girlfriend). This last example is really only used among black Americans.

Hi im auditioning for a school play and I was wondering how to speak with a British accent.when I try to speak British,My friends say it's more like austrailian when I say ''Oi mate''or ''lets put another shrimp on the barbe(barbeque)''anyway, is there any help

thanks
Confused citizen

In babytalk, a "boo-boo" is a minor injury.

To confused citizen:
It sounds like you are playing the role of a fisherman, are you not? I really can't conceive anyone except fishermen saying "Oi mate". What accent you want to imitate really depends on the character's station in life and locality (e.g. Home Counties, East Anglia, Yorkshire, etc.).