Green’s Dictionary of Slang

1. a police raid.

1987

King Tee & Mixmaster Spade ‘Ya Better Bring a Gun’ 🎵 You can get away with murder, cause they murdered the cops / Cause they said they tried to run a bumrush on Watts.

2. a stampede, esp. of a crowd wanting to get into a rock concert or film show (usu. without tickets and dependent on force of numbers to overwhelm the security guards).

1988		Ice-T ‘I’m Your Pusher’ 🎵 Paparazzi on the bum rush for pictures.
2002		Cypress Hill Sl. Gloss. 🌐 bumrush: someone is under attack by an enraged mob.

3. an attack by a gang.

1988

NWA ‘Gangsta Gangsta’ 🎵 A bum rush, but we call it rat pack.

4. any form of pressure, e.g. the need to make a quick decision.

2008

‘Grandmaster Flash’ Adventures 138: ‘If you have a contract with him,’ Joe says, ‘we'll take care of all that.’ Sylvia finishes for him: ‘the important thing is that we start working together ASAP.’ Doesn’t feel right, this bum-rush.