What is the meaning of the word "game"?

Definitions:

(games) the score at a particular point or the score needed to win noun
- the game is 6 all
a contest with rules to determine a winner noun
- you need four people to play this game
a single play of a sport or other contest noun
- the game lasted two hours
an amusement or pastime noun
- they played word games
frivolous or trifling behavior noun
- for actors, memorizing lines is no game
the game equipment needed in order to play a particular game noun
- The child received several games for their birthday.
your occupation or line of work noun
- he's in the plumbing game