1. A nickname for someones penis, implying it's large size.
2. Someone who can drink alot. Ex. Frank the tank from that movie with Will ferrel.
3. A tubby ass mutha fucka. Someone who isn't going to get layed for a while.
4. an armored vehicle
1. Hey eric you have a small dong.
Shut up asshole this thing is a tank 2. Douche:guys im a hard ass watch me drink this whole six pack by myself. you: wow what a tank.
3. That bitch gave me herpes! How'd she get layed if she was a tank?
4. I used to drive a tank back in nam'.