mustard dorkin Share definition Flag (must-are-d dork-in) the act of placing mustard from the bottle near, in or around the anus. yo, pete was so f'ed up jay made a salad in his hair, put pickles in his shoes, and gave him a mustard dorkin. mustard dorkin by jjigga August 21, 2009 0 0 Get merch Get the mustard dorkin mug. Buy Now — $32.95 See more merch