2. Also a person who has performed an unfathomable action (positive)
Guy 2: Ah, you tank!
Guy 1: I just done a 1000 press ups!
Guy 2: You Tank!
Verb: To "tank", or "tanking", would be the action of performing the duties of the tank as described above.
2.V. The warrior is tanking the mob right now.
3.V. Do you think you can tank this mob for us?