To cadillac 

to relax, chill, typically after one boom-booms.

To cadillac, you need to calm your ass down and chillax.

Greg: When we get done boom-boomin', we'll cadillac...

Cory: What the hell are you sayin???

To cadillac by jisdbhu April 29, 2010

Speak to a man about a Cadillac

Another alternate phrase meaning going to take a piss, uttered to a friend in a bar.

Man 1: I'm going to speak to a man about a Cadillac.
Man 2: Cool, I'll order us another round.

Speak to a man about a Cadillac by Smokin' Bitch Magnet February 4, 2006