tap on glass 

To tap on the window of a car when you see the police. Done to give you the luck to not get caught. Originating in Parker, Colorado.

Tap on glass, save your ass.

tap on glass by Muthafuckinnigga May 14, 2015

Tap on the glass 

Can mean two things. A hearty clink of two bottles being knocked together orrrrr... when your x boy friend comes to your work... preferably a school and starts tapping on the glass making the children feel like they are about to be shot dead (this is in America by the way) and the teacher as though she is about to be obstructed.

Wow... what a tap on the glass

Tap on the glass by Magic. Feetus December 8, 2019