What is 1337 M4573r?
1)A 1337 m4573r is one that is n0b13 in the 1337 arts, quite possible a pwning gamer, and otherwise totally kickass on the net. This person could possibly be a 6 year old pwning your ass on Halo online, or maybe a 42 year old in his parents basement.
2)Largo on megatokyo
1)d00d, 7h47 1337 m4573r pnd j00'5 455. n00b.
2)1337 m4573r Largo! You have a class to teach!