Is “Tanking” a Scrabble word?

1.To fail or fall (often used in describing the economy or the stock market); to degenerate or decline rapidly; to plummet.

2.To attract the attacks of an enemy target in cooperative team-based combat, so that one's teammates can defeat the enemy in question more efficiently.

3.To put (fuel, etc.) into a tank.

1.To stand; to tolerate.

1.A session of being immersed in a tank.