knock about

The ruling had the effect of knocking about $16 million off expected income from the property owners.

But regulators turned down the request last month, knocking about 20% off Metro's share price.

It wasn’t a truant officer at his door, though — no one had ever come knocking about that.

There will always be twisted murderers knocking about, and Luther can't resist when they bait him.

An asteroid minding its own business not too far from Earth is about to get knocked about by a visitor from our planet.