1447 Share definition Flag Word used to baffle mindless l33t speakers and force them to unwittingly correct your grammar. A: Wow I'm so 1447, I can't believe I pounded you. B: WTF is 1447, don't you mean 1337 and pwnd? Joo n00b! 1447 by |Mac10| Garden Vegetables June 4, 2004 Get the 1447 mug.