Ragged
A flop that doesn't seem to help anyone much..

Railbird
Someone who hangs around a poker room and watches the game rather than playing.

Rainbow
A flop that contains three different suits and no flush can be made..

Raise
Increasing the bet amount made by another player.

Rake
An amount of money taken out of the pot by the dealer on behalf of the card room.

Rank
The numerical value of a card.  

Rap
To knock on the table to indicate the player has checked.

Razz
Seven Card Stud where the lowest five cards win the pot.

Ring Game
A regular poker game, not a tournament.

River
The fifth and final community card put out face up by itself. Also called "fifth street".

Rock
Tight, conservative player.

Rounder
A professional player who makes the rounds of the big poker games..