Definition: To move your car so that it is in front of another car to force it to drive slower.
( Also: Cut Off)
1. To cut something into many pieces.
2. To be upset by something.
E.g.1. We were dangerously cut up at the traffic lights by a big red car.
E.g.2 It is against the law to cut people up when driving.
This phrasal verb can be separated.