Narrow the Field
To bet or raise in order to scare off other players whose hands are currently worse than yours, but have the potential to improve.
Nit
To bide your time, patiently waiting for a playable hand.
No-Limit Poker
A game in which players can bet as much as they have in front of them on any given round.
No-Limit
A version of poker in which a player may bet any amount of chips (up to the number in front of him) whenever it is his turn to act. It is a very different game than limit poker. The best treatise on no-limit poker is in Doyle Brunson's Super/System.
Nut Flush
The highest possible flush that can be formed with the cards on the board.
Nut Straight
The highest possible straight with the cards on the board.
Nuts
The best possible hand at any point in the game, a cinch hand.
Nuts
The best possible hand given the board. If the board is Ks-Jd-Ts-4s-2h, then As-Xs is the nuts. You will occasionally hear the term applied to the best possible hand of a certain category, even though it isn't the overall nuts. | 
