Top definition
A man's sexual organs, as opposed to his usual so-called-brain, the upstairs brain.
Mike wasn't digging Jen, but three beers later he was thinking with his downstairs brain. Now he has herpes.
by MWazza April 17, 2009
Mug icon

The Urban Dictionary Mug

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Buy the mug