Mooslims Share definition Flag Americans who were born in a Muslim family but don't follow the traditions. The "moo" comes from the freedom to eat beef...you are what you eat. Mahammod: Dude I f*ckin love in-n-out Jeff: WTF!? Aren't you NOT allowed to eat beef? Mahammod: Naaah man me and my bros are mooslims. Mooslims by AyeWhole January 7, 2011 Get the Mooslims mug.