Cliffin' Share definition Flag When something you do goes unexpectedly wrong and you look like a dumbass. Cliffin' could happen at anytime of the day and anyone can be Cliffin'. One person: Dude I just burnt my finger with the lighter!Second person: You be cliffin' Cliffin' by Annie Recksun October 30, 2011 Get the Cliffin' mug.