beat it!
used to tell someone to leave at once, because they are annoying you or should not be there

[TahlilGaran] Dictionary of Contemporary English ▲

beat it
to go away immediately.
I told the kid to beat it, and that's the last I saw of him.

She said she was going to pack her bag and beat it back to Tennessee.

Usage notes: often used as an order:
Go on, beat it!

Etymology: based on the phrase beat a retreat (= leave a battle quickly)

[TahlilGaran] English Idioms Dictionary ▲

Beat it!
[mainly American, informal]
a rude way of telling someone to go away.
OK you kids, beat it!

[TahlilGaran] English Idioms Dictionary ▲

beat it
v., slang To go away in a hurry; get out quickly.
When he heard the crash he beat it as fast as he could.
■ Often used as a command.
The big boy said, "Beat it, kid. We don't want you with us."
Compare: CLEAR OUT², LIGHT OUT, HEAD FOR THE HILLS.

[TahlilGaran] English Idioms Dictionary ▲