Swampy Share definition Flag A term used to describe a friend when he's acting weird or paranoid all of a sudden. What do you mean you don't want to go anymore, Dude, why are you being so swampy right now? Swampy by Kevin Buan March 16, 2010 0 0 Get merch Get the Swampy mug. Buy Now — $32.95 See more merch