Action poker
1) The relative liveliness of a game, often measured by the
frequency and quantity of bets and raises. "This game has
a lot of action." Often part of the phrase fast action.
2) Being required to act. When it's your turn to do something,
someone might say,
"It's your action," or, "The action is up to
you."
3) That portion of the pot that a player short of the full bet
can win a multiple of.
In a no-limit game, if John bets $100, Jim calls the whole $100,
and you call,
but you have only $20, you are said to have $20 worth of action
in the pot. A side pot of $160 will be created between John
and Jim; $20 of John's bet goes into the main pot, as does $20
of Jim's bet, and all of your bet; you can win the $60 main
pot if you win.