DM

In video games, DM stands for Desperation Move.
When playing a video game, specifically an RPG/JRPG, it's the strongest move during a boss fight. They usually happen halfway or 3/4 of the way through the battle and are a bitch to survive. These will usually hack away your HP in seconds if you do not dodge or block properly.

I'm fighting my way through the Data Organization XIII battles but Master Xehanort's DM keeps killing me.

Xemnas' Desperation Move is a pain in the ass to dodge.