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)
Go away, as in We should beat it before the food's all gone. This term is rude when used as an imperative, as in Stop pestering me-beat it! [Slang; late 1800s]