Main Tank Difference
MTD is an extremely common acronym used by Professional players of the game Overwatch. It means that the team who won the match did so because that team had a better main tank who carried them to victory.

A person who doesn't realize they are transgender yet, or is in denial; an undeveloped transgender person. When they realize, it's referred to as the "egg cracking."

MTD, or MySpace Transmitted Disease, is something you implicitly have when you are added by a girl with a webcam. They are nasty people, who in all likeliness do not care who they ask to be their freinds, they just want to be "watched". These can also be contracted by people who are added by MySpace whores, aka people with over 200 friends who are not musicians.

Mentally Transmitted Disease

MTD is the maximum time a critical process can be down, or hindered in some way, without irreparable harm to the business. It’s typically calculated as part of a business impact analysis (BIA).

This is someone of a myspace nature addiction. (Myspace Transmitted Disease)

Acronym mean "mouth to dick".