OMMF Share definition Flag acronym - Oh My Mother Fucker - to be used in place of "OMG" in order to separate church from chat. 1) OMMF ! That chick has some big ass titties ! OMMF by Stoner Army October 22, 2008 0 0 Get merch Get the OMMF mug. Buy Now — $32.95 See more merch