mooshibooboo Share definition Flag (n.) to be fat in a humorous way\ fluffy \ little \ little behavior Beto is a mooshibooboo!Kim's butt is mooshibooboo equivalent mooshibooboo by Hank Flemington May 7, 2009 0 0 Get merch Get the mooshibooboo mug. Buy Now — $32.95 See more merch