ttfy Share definition Flag Acronym for "Tough titty for you"; a way of derisively dismissing someone else's argument for being annoyingly petulant. Donald Trump: "Waaahhhhh, reality is conspiring against me!" Joe Biden: "TTFY" ttfy by PrinceLotor November 11, 2020 0 0 Get merch Get the ttfy mug. Buy Now — $32.95 See more merch