Smithing off Share definition Flag The act of masturbating in public places. For example a school or a work place. John: Hey did you see that kid smithing off in class.Marshall: yeah dude that is so disgusting. Smithing off by M.J. Moobs September 1, 2009 0 0 Get merch Get the Smithing off mug. Buy Now — $32.95 See more merch