1 - In Martial arts, A kind of over-cooperation; What a willing assistant does to demonstrate what is actually faked.
2 - A term in Gaming describing the actions of a "Tank", which is the character kept as the primary interest of enemies so as to be the primary absorber of damage.
Martial arts ∞
If I step in the line of fire to take a hit for you, I am tanking for you. If I purposely fall to assist your throw, I am tanking for you. Tanking can be, but isn't always, deceptive.