vitamin-a Share definition Flag Referencing a want, or need for a vulumptuous buttox or 'ass'. Usually used by males to describe the attractive physical characteristic of 'booty' on the opposite sex. Damn, that chick has some vitamin-a to spare. vitamin-a by Jameson January 31, 2005 0 0 Get merch Get the vitamin-a mug. Buy Now — $32.95 See more merch