A hat that old perverts wear and when they see a hot gal with a nice ass, they drop it and request the girl pick it up, explaining they're old and therefore can't bend over. When she does, as most girls do, they bend over, and the old man takes a good look at her ass, as the girl suspects nothing. This was seen in an episode of the fresh prince.
Also a form of pitching
Kid 1: Hey did you watch the episode of fresh prince where will is in the hospital
kid 2: yeah wasn't that famous old dude there with him, the pervert
kid 1: the one with the lucky hat, yeah, that nurse's ass was fine!