Bui Share definition Flag Most used Bahamian slang term. Has many uses such as emphasizing a command that follows it or replacing certain words, such as boy. BUI you ugly dread.BUI TAKE IT EASY YANNO KING Bui by Freeportboi January 3, 2010 0 0 Get merch Get the Bui mug. Buy Now — $32.95 See more merch