gidunk Share definition Flag A word used in Navy, often used to describe junk food. "Gidunk" is the sound a candy bar makes when it falls in the vending machine. Please section leader, can i have a gidunk card so i can go to the gidunk line and get some snacks? gidunk by Jeff (USN) January 3, 2008 0 0 Get merch Get the gidunk mug. Buy Now — $32.95 See more merch