3m0 Share definition Flag emo in hacker speak. in the fashion of 1337 = elite and whatnot. OMG that n00b is emo 3m0. i bet she cried when i pwnd her the other night 3m0 by Rachel Horowitz April 15, 2006 0 0 Get merch Get the 3m0 mug. Buy Now — $32.95 See more merch