beat up

beat up  {v.},  {informal}
To give a hard beating to; hit hard and much; thrash; whip.
When the new boy first came, he had to beat up several neighborhood bullies before they would leave him alone.
- Used with "on" in substandard speech.
The tough boy said to Bill, "If you come around here again, I'll beat up on you."
Categories: {informal} {v.}