Cheffin' it up Share definition Flag To cook; usually when making something really tasty. Often used when having fun in the process. Dan: "What are you doing over there?"Dave: "You know man, I'm cheffin' it up" Cheffin' it up by Biefer September 14, 2009 0 0 Get merch Get the Cheffin' it up mug. Buy Now — $32.95 See more merch