Definitions by Websters English Dictionary

Plumbers ass 

The act of having ones ass crack visible over the top of their pants. Often seen in women wearing low rider jeans. Derived from fat plumbers whose asses creeped out of the back of their pants as they fixed the sink.

She should at least wear a thong so we sdon't have to see that plumbers ass.

Plumbers ass by Websters English Dictionary January 25, 2004