cud-sack Share definition Flag A large bag filled with partly digested food that has been spit up. You are a cud-sack., John was annoyed with Brian. So John told Brian, "You are a cud-sack." cud-sack by Amelia.Summers April 19, 2017 0 0 Get merch Get the cud-sack mug. Buy Now — $32.95 See more merch