HL2DM 

HL2DM
Short for Half-Life 2 Death Mach.
An add-on created by Valve for the game Half-Life 2

Hey wanna play HL2DM tonight?

HL2DM by grudgE .::NK::. August 31, 2005

HLDM 

Acronym for Half Life Death Match

Player: Let's get it on HLDM style!
Player2: How about let's not get it on...perv.

HLDM by Lozer T. User September 2, 2005