T.O.S.S Share definition Flag T= Triippin' O= On S= Some S= Shrooms Dude that guys just T.O.S.S aww man, i was totally T.O.S.Sin' last night! T.O.S.S by JoeJoe67 March 6, 2008 0 0 Get merch Get the T.O.S.S mug. Buy Now — $32.95 See more merch