Unfinished basement 

The not-completely-wiped asshole or the act of tossing the salad of someone with said asshole.

Phyllis nearly threw up when she licked Chris' asshole and discovered that he had an unfinished basement. She promptly bought him an extra roll of TP.

Unfinished basement by JotaBug June 27, 2009

Unfinished Basement 

A.k.a. "going commando", sporting an unfinished basement implies wearing no under garments.

Go pants Todd, he's got an unfinished basement.

Unfinished Basement by liquidcrack January 21, 2003

unfinished basement light 

Unfinished basement light is used on things that don't do their job properly. The basement is dark and the light doesn't work to light it up. Also used in places where a construction worker decides to quit and handed his coworker a sock and said "the basement light is unfinished".

Lisa, you are an unfinished basement light to this project.

unfinished basement light by potatoali August 10, 2017

unfurnished basement 

Not wearing underpants.

"There's nothing like an unfurnished basement!" exclaimed Douglas, while wearing a kilt.

unfurnished basement by nudgeee June 18, 2008