To send a Direct Message on twitter

when you've done something so cringe you can't stop replaying it in your head and it stops you from getting on with your every day life

Commonly used on twitter. It means to direct message.

To "DM" somebody u direct message them .

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

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.