Dumbass-Itus Share definition Flag Its when he/she is a dumbass and infects people with dumbass-itus Boy: I banged ya mum Girl: Ohh shit you gave ma mum Dumbass-Itus Dumbass-Itus by testtube baby June 18, 2016 0 0 Get merch Get the Dumbass-Itus mug. Buy Now — $32.95 See more merch