When a member of the opposite sex inserts a finger in your asshole in order to insure that you perform at your peak. (Typically done before a big athletic event)
Hey man, I heard you have a big race coming up this weekend.

Yeah, I've got to get my girlfriend to harness my power so we can beat those retards from Williams.
by Butter Deez Nuts March 6, 2008
Get the harness my power mug.