Thumb of Zeus Share definition Flag A choad that is at least six inches in length. Because of its girth, it could be mistaken for a balloon in the pants. At first I thought he had a balloon in his pants, but it turned out he had a Thumb of Zeus. Thumb of Zeus by The Piano Man August 5, 2012 0 0 Get merch Get the Thumb of Zeus mug. Buy Now — $32.95 See more merch