To send a Direct Message on twitter

Commonly used on twitter. It means to direct message.

DM - Dungeon Master. The person who makes up the story and stuff in a game of Dungeons and Dragons.

To "DM" somebody u direct message them .

Designated Marksman. military marksman role in a U.S. infantry squad. The DM's role is to supply rapid accurate fire on enemy targets at ranges up to 870 yds with a highly-accurate semi-automatic rifle equipped with a telescopic sight. Like snipers, DMs are trained in quick and precise shooting, but unlike the more specialised "true" sniper, they are also intended to lay down accurate rapid fire.

abbreviation for Dick Move. Not in reference to actual penis movement, but refers to action made by impolite person causing another to take offense.