Blighyarding Share definition Flag The act of causing trouble or mischief. The term is Gaelic. Timmy, if you don't quit all that blighyarding, I'm gonna slap the tast right outta your mouth. Blighyarding by BostonMick March 1, 2009 0 0 Get merch Get the Blighyarding mug. Buy Now — $32.95 See more merch