Game

A playful or competitive activity.

A video game.

(nearly always singular) A field of gainful activity, as an industry or profession.

"He's in the securities game somehow."

Something that resembles a game with rules, despite not being designed.

"In the game of life, you may find yourself playing the waiting game far too often."

To gamble.

To play card games, board games, or video games.

To exploit loopholes in a system or bureaucracy in a way which defeats or nullifies the spirit of the rules in effect, usually to obtain a result which otherwise would be unobtainable.

"We'll bury them in paperwork, and game the system."

(of males) To perform premeditated seduction strategy.

Willing to participate.

(of an animal) That shows a tendency to continue to fight against another animal, despite being wounded, often severely.

Persistent, especially in senses similar to the above.

Injured, lame (of a limb).