Y.O.L.O. Share definition Flag Acronym for You Only Live Once.Now get off your computer and go outside. George came to the party with the word Y.O.L.O. on his shirt and got things started. Y.O.L.O. by THC420 December 27, 2009 0 0 Get merch Get the Y.O.L.O. mug. Buy Now — $32.95 See more merch