clabornism Share definition Flag The act of lying so convincingly that you convince yourself it is the truth, while in fact being completely full of shit. That guy just tried to tell me he was the king of Siam. He must have a degree in clabornism. clabornism by Urfos October 18, 2013 0 0 Get merch Get the clabornism mug. Buy Now — $32.95 See more merch