postin' up 

(verb): To make out against a wall; up against a wall.

Guy 1: Hey, where's Jack and Jill?
Guy 2: Probably postin' up against behind the English building..

postin' up by Jay Ell December 4, 2007

Postin Up 

The act of going to a public place usually a gas station, street corner, by a deli or convenience store and hanging out and standing in a way so people will know you holding / selling drugs.

Where is GQ go? He is at the station postin up...

Postin Up by OcalaAwesome April 20, 2013