underwire Share definition Flag A trashy tattoo that follows a woman's curves under her breasts, the way an underwire in a bra would. The 2000' tramp stamp. When you meet a tatted chick with an underwire, you know she's easy! underwire by ThinkingTooHard January 6, 2021 0 0 Get merch Get the underwire mug. Buy Now — $32.95 See more merch