DM

• Danger Mouse.
• Duncan Martin (And I Claim My Five Pounds)?
• Dungeon master
• Decamolar - a (preposterously large but still metric) unit of concentration; water at room temperature has a concentration of ~5.5 DM.
• The Deutsche Mark; now sadly defunct - or is it?
• Duncan Mc Combie
• Doctor 'Doc' Marten, a brand of boot