idgafau Share definition Flag Stands for "I don't give a fuck about you." Usually slang, not usually acceptable in an essay or formal letter. "Yo I'm the best you'll ever get!" "Nah bitch idgafau." idgafau by cretan4bleedin May 2, 2016 0 0 Get merch Get the idgafau mug. Buy Now — $32.95 See more merch