Definition of rack (noun)

A geometric form, usually aluminum, wooden or plastic, used to assist in setting up balls in games like eight-ball, nine-ball, and snooker. The rack allows for more consistently tight grouping of balls, which is necessary for a successful break shot. In most games a triangle-shaped rack capable of holding fifteen balls can be employed, even if the game calls for racking less than a full ball set, such as in the game of nine-ball. For further information, see the Rack (billiards) main article.
In some games, refers to a single frame.

24 Random Essential Billiards Terms

In snooker, the second-highest value colour ball, being worth six points.
Also lady's aid or girly stick. A denigrating term for the mechanical bridge.
The intersection of the head string and long string, which is usually not marked on a table with a spot decal, unlike the foot spot, though some pool halls mark both spots so that racking can be done at either end of the table, and wear on the cloth from racking and breaking is more evenly distributed.
Chiefly British: Same as shark (senses 1, 2). The term appears in lyrics from The Mikado (1884) in relation to billiards, and developed from sharper (in use by at least 1681, but now obsolete) meaning "hustler" but not specific to billiards.
British term referring to the base or metaphorical "feet" of a ball that rattles in the jaws of a pocket before eventually dropping. Usually said of an object ball for which the intention was to pot it.
Also straight eight-ball. Same as bar pool. Not to be confused with the games of straight pool or straight rail.
A joint type which makes it possible to screw and unscrew the butt and shaft very quickly; faster than standard threads.
Three equally spaced diamonds are normally between each pocket on a pool table. On a carom table, the pockets themselves are replaced by additional diamonds. Diamonds get their name from the shape of the markings traditionally used; though many today are round, square, etc., these rail markings are still referred to as "diamonds".
(Chiefly British) Said of an object ball that can easily be reached by the cue ball, or of a pocket that can easily be reached by a selected object ball, usually directly (i.e. without intervening kick, bank, carom, kiss or combination shots).
The non-red colored ball meant to be pocketed in a game of snooker, or the next ball meant to be pocketed in a particular game.
Given to the opposite player after a scratch on the cue ball has been played. This means the player with the cue ball in hand can position it wherever on the table he pleases. Sometimes there are restrictions as to where on the table the ball can be placed: in the kitchen, within the half circle, within the D. This is also known as cue ball in hand.
This refers to the distance of deflection that the ball comes off of the cue stick after a hit is applied with side spin on it.
This is a series of angled rails present within some pool tables that directs pocketed balls to a central location on the table for retrieval after the game.
American Poolplayers Association. This is the largest association of pool players in the world, and includes The Canadian Poolplayers Association. With numerous tournaments, including the U.S. Amateur championship, they are a force on the competition scene.
The APA has established the use of the "Equalizer" which offers handicaps to players and equalizes the playing field like in golf.
A player of cue sports.
A pool cue designed for breaking. Along with sometimes having unusual weight or balance to build maximum speed for the cue ball, some break cues have stiffer shafts and special breaking cue tips to transfer energy more efficiently to the cue ball.
In blackball, a penalty conceded by a player after a fault. The incoming opponent is then allowed to miss twice before the faulting player is allowed another visit. Many local rules state the in-hand from the "D" or baulk (or if the opponent potted the cue ball, from anywhere) nature of the second shot is lost if a ball is potted on the first shot, that it is lost if the ball potted in the first shot was that player's last coloured ball (object ball in their group), and/or that there is only ever one shot on the black after a fault.
Same as follow (top spin).
A style of game play in which as many players are allowed to join as the participants choose, and anyone can quit at any time. The term, most often used in the context of gambling, is borrowed from poker. The folk games three-ball and killer are usually played as open ring games, as is Kelly pool.
By extension, a multi-player game that anyone may initially join, but which has a fixed roster of competitors once it begins, is sometimes also called a ring game. Cutthroat is, by its nature, such a game. A famous regular ring game event of this sort is the Grady Mathews-hosted six-player, $3000-buy-in ring ten-ball competition at the annual Derby City Classic.
A nine-ball ring game is played by more than two players. Safeties are not allowed.
To play for money and lull a victim into thinking they can win, prompting them to accept higher and higher stakes, until beating them and walking off with more money than they would have been willing to bet had they been beaten soundly in the beginning. The terms hustler, for one who hustles, and hustling, describing the act, are just as common if not more so than this verb form.
In a tournament, to place high enough to receive a payout. E.g., in a tournament that pays from 1st down to 5th places, to be at least 5th place is to be in the money.
This is a tip tool for cleaning the edges of you tip after mushrooming occurs.
Artistic pool is a trick shot competition, inspired by the related discipline of artistic billiards.
Also massé shot. A steep curve or complete reversal of cue ball direction without the necessity of any rail or object ball being struck, due to extreme spin imparted to the cue ball by a steeply elevated cue. For Example: shooting with extreme english by holding the cue at a position of 30-90 degrees while applying left or right spin.