mstk Share definition Flag Slang for 'Mistake'. "Mstks hapn.""I like making mstks!""Mstks are fun!""U r mkin a big mstk! Kudos!" mstk by The Pseudozombie August 13, 2012 0 0 Get merch Get the mstk mug. Buy Now — $32.95 See more merch
