GMX 

Name given to someone whose voice resembles that of former Def Jam recording artist, and hip hop icon DMX, and name also starts with the letter "G". ie, Glenn, Garry, Greg, Gordon, etc..

Person 1 : "Yo son, that Supa fly ass cracker Glenn sounds just like DMX!"
Person 2 : "You talking about Glenn with the crystal clear dark grey eyes, amazing personality?!?"
Person 1 : "Ya dumby! Glenn, the one that's mad cut, and has like 8 pairs of Louboutin sneakers"
Person 2 : " We call him GMX because he sounds just like DMX."
Person 1 : " Luckily he's in love with that mad beautiful Polish girl because if he wasn't he'd be taking all our bitches for sure!""
Person 2 : "NO DOUBT!!"

GMX by G-MacbookPro_witdaRetinaScreen January 17, 2015

GMX 

Grand Masta Caspa. This is a well known gamer tag for all important games. If you see this in the high scores; you know that the game is legit and that reaching that level may be impossible!

GMX has first place in that game too?!

GMX by Grand Masta X February 3, 2010