mustajizz Share definition Flag The watery mustard juice that squirts out of the mustard bottle on the first squirt. "Eewww gross what is that yellow watery stuff all over my hotdog, oh its just the mustajizz" mustajizz by funkymunkeymel April 18, 2008 0 0 Get merch Get the mustajizz mug. Buy Now — $32.95 See more merch