Another poker term for "betting," that is, to start the action is to start the betting.

Ante:

A small sum of money, placed in the pot by each player. Antes are used in Stud and Draw, but not in Hold'em or Omaha.

Big Blind:

A bet that must be posted by the player two seats to the left of the button. It is equal to the amount of the smaller betting limit in a game, for example, in a 10-20 game, the big blind would be $10.

Blind:

Forced bets placed in the pot by the first two players in front of the dealer button, in Hold'em and Omaha. See "small blind" and "big blind."

Bluff:

To bet when you hold a weak hand, hoping that the intimidation factor of your bet can win the hand.

Bring-in:

In Stud, a bet that must be made on the very first betting round. Usually the player showing the lowest card is forced to make a bet; in some games, the player showing the highest card is forced. The bring-in applies only on the very first betting round, though. On all further rounds, the player showing the highest hand on board has the OPTION to bet first, but need not.

Call:

To match a bet that has been made.

Check:

To possess the option to bet, but decline. A player cannot check once someone else has bet; at that point, the player must call, raise, or fold. But if no one has yet bet, a player can check, allowing the betting option to pass to the next player.

Check-raise:

To check, indicating weakness, with the intention of raising after someone else bets.
Check-raises are allowed in all casino poker games; in some home games, they are frowned upon.

Fifth Street:

The fifth community card in Hold'em or Omaha (in these games, 5th street is more often called "the river."). Also sometimes used to refer to the fifth card received in 7 Card Stud.

Flop:

In Hold'em or Omaha, the first three community cards, turned up all at once.

Fold:

To drop out of a hand.

Fourth Street:

The fourth community card in Hold'em or Omaha (in these games, 4th street is more often called "the turn."). Also sometimes used to refer to the fourth card received in 7 Card Stud.

Hole cards:

Cards that are face down and cannot be seen by the other players.

Kicker:

Two meanings.

1) A single card kept along with a pair, in Draw, in an attempt to make two pair. For example, someone might keep 3-3-K, drawing two cards, in the hope that he might get either a three (for trips) or a King (making two pair, Kings-up).

2) The highest single card held by two players in Hold'em who each hold the same pair. For example, if the board in Hold'em is A-10-8-5-2, and Player One holds A-J as his hand, and Player Two holds A-Q, each player has a pair of Aces, but Player Two has a better kicker and would win the hand.

Narrowing the Field:

To bet or raise in the hopes that you will drive out some players whose hands are currently worse than yours, but who might improve if allowed to stay in.

Nuts, The:

The best possible hand. This phrase is almost always used in the context of a particular hand (otherwise "the nuts" would just be a term for a royal flush). For example, in Hold'em, a player holding 8-9 would hold "the nuts" if the flop came 6-7-10. At that moment, the 6-7-8-9-10 straight is the best possible hand. However, if the Turn card were a Jack, and the River a Queen, a player holding A-K would then have the nuts-a 10-J-Q-K-A straight.

Pot:

The money in the center of the table, being contested by the players still remaining in the hand.

Rake:

The amount of money the casino takes from the pot to make money from the poker game. In low limit games, the casino usually rakes some percentage of the pot, usually a maximum of 10% of the pot. In higher limit games, the casino makes money either by charging players an hourly fee to play, or by collecting a fee each time a player holds the button.

River:

In Hold'em or Omaha, the fifth and final community card. Also sometimes called fifth street.

Rock:

A player known to be very conservative, who usually bets or raises only when he has a very powerful hand.

Small Blind:

A bet that must be posted by the player one seat to the left of the button. It is usually equal to one half of the smaller betting limit in a game, for example, in a 10-20 game, the small blind would be $5. Occasionally, the small blind is some other fraction of the big blind.