FD Share definition Flag verb. (EF-DEE) To make plans and then break them without a call or other notice "He said he'd be here ... you believe he just FD'ed us again?" "That's an FD, man. You just "FD'ed us!" FD by F Dom December 3, 2007 0 0 Get merch Get the FD mug. Buy Now — $32.95 See more merch