Definition of Double the pocket

Literally, a pocket, but generally used in the phrases losing hazard - potting (pocketing the cue ball off another ball - and winning hazard - using the cue ball to pot another ball - the two types of legal shots that pocket balls in games in which the term is used at all, which is very few today. The term principally survives in English billiards, in which both types of shots are point-scoring. Formerly, a large number of different games made use of the two types of hazards as point scorers or losers in various different ways (thus their suggestive names). The term ultimately derives from holes or pockets in the table to be avoided, in very early forms of billiards. While the terms are disused in pocket billiards today, their lingering effect is obvious, as the vast bulk of such games focus on making winning hazards and avoiding losing hazards (a notable exception being Russian pyramid in which both are legal shots).
In golf billiards, an area of the table (sometimes marked) that a player will be penalized for entering if their ball does not leave. Derives from the use of the term in the outdoor game of golf.

A Carom game with lines drawn to form rectangles that restrict play and reduce the potential for high runs.

To determine the order of play, players (representing only themselves, or teams) each simultaneously shoot a ball from the kitchen (or in British games, from the baulk line) to the end rail and back toward the bottom rail. Whichever shooter's ball comes to rest closest to the bottom rail gets to choose who breaks the rack. It is permissible but not required for the lagged ball to touch or rebound from the bottom rail, but not to touch the side rails. Lagging is usually a two-party activity, though there are games such as cutthroat in which three players might lag. In the case of a tie, the tying shooters re-lag. The lag is most often used in tournament play or other competitions. In hard-break games like nine-ball and eight-ball the winner of the lag would normally take the break, while in soft-break games like straight pool would likely require the loser of the lag to break, since breaking would be a disadvantage.

When a particular ball is given as a handicap in nine-ball, designating that ball in turn means that it must be made in rotation, when it is the lowest numerical ball remaining on the table, and cannot be made to garner a win earlier in the game by way of a combination, carom or any other shot. For example, if a player is spotted the 8 ball, he only wins by making that ball after balls 1 through 7 have been cleared from the table.

An organization that promotes competitive, usually team, amateur cue sports, most commonly pool, especially eight-ball and nine-ball, although there are also well-established snooker leagues. Some leagues, many of which are decades old, are entirely local and either informal or incorporated, and may use their own local rules or may have adopted more widely published rulesets, such as those of the WPA. Other leagues are organized on a multi-regional or even international level, and may be non-profit or for-profit enterprises, usually with their own fine-tuned rule books. Despite differences, the largest leagues are increasingly converging toward the WPA rules, with the exception of the APA/CPA, which retains rules much closer to US-style bar pool. At least four major pool leagues hold international championships in Las Vegas, Nevada annually (APA/CPA, BCAPL, VNEA and ACS/CCS). Some leagues also offer one-on-one tournaments, scotch doubles events, artistic pool competition, and other non-team activities.

A cut shot in which if a line were drawn from the cue ball to the rail behind the targeted object ball, perpendicular to that rail, the object ball would lie beyond the line with respect to the pocket being targeted.

A shot in which the cue ball is struck above its equator with sufficient top spin to cause the cue ball to travel forward after it contacts an object ball. When a cue ball with follow on it contacts an object ball squarely (a center-to-center hit), the cue ball travels directly forward through the space previously occupied by the object ball (and can sometimes even be used to pocket a second ball). By contrast, on a cut shot, a cue ball with follow on it will first travel on the tangent line after striking the object ball, and then arc forward, widening the carom angle.

Also pills, tally balls and shake balls. Small, round markers typically numbered 1 through 15 or 16, which are placed in a bottle for various random assignment purposes, such as in a tournament roster, to assign order of play in a multiplayer game, or to assign particular balls to players in games such as kelly pool.

Nine Ball is a rotation game so a player must hit the lowest numbered ball first.
The object of the game is pocket the 9-ball on any legal shot.

A rule in blackball whereby after an opponent has faulted and thus yielded two shots, if the incoming shooter pots a ball on the first shot, (s)he is still allowed to miss in a later shot and take a second shot in-hand (from the "D" or from baulk, or if the opponent potted the cue ball, from anywhere)—even on the black, in most variants. Also called the "two visits" rule; i.e., the two penalty shots are considered independent visits to the table, and the limiting variants discussed at two shots below cannot logically apply.

This is English that turns into reverse English after contact with the object ball. This will close up the angle on a bank.

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.

This describes balls that are not able to be made in a pocket, either because they are high up on the table, in a different pocket, or in a cluster that makes the shot difficult. This condition of being out of play obviously exists on different difficulty levels.

The sides of a table's frame upon which the elastic cushions are mounted. May also be used interchangeably with cushion.

This is a particular ball which lends itself to be used as a "blocker" or a "protector."
To use a particular ball as security by playing a safety or leaving it where it will act as one.

Side spin on a cue ball on the opposite side of the direction of the cut angle to be played (right-hand english when cutting an object ball to the left, and vice versa). In addition to affecting cue ball position, outside english can be used to decrease throw.

Either of the balls on the lateral extremities of a racked set of balls in position for a break shot; the two balls at the outside of a 15-ball rack in the back row, or the balls to the left and right of the 9 ball in nine-ball's diamond rack-shaped opening set up position. In nine-ball It is seen as a reliable sign of a good break (which is normally taken from close to either cushion in the kitchen) if the opposite wing ball is pocketed.

New Zealand Billiards and Snooker Association.

The World Pool-Billiard Association (WPA) is the international governing body for pocket billiards (and also sactions rules and events for carom billiards games as well, in cooperation with other bodies). The group was formed in 1987, and was initially headed by a provisional board of directors consisting of representatives from the United States, Japan, Sweden, and Germany.

Five-pin billiards is a today usually a carom but sometimes still a pocket form of cue sport, popular especially in Italy and Argentina but also in some other parts of Latin America and Europe, with international, televised professional tournaments. The game is sometimes referred to as Italian five-pins or Italian billiards.

Actual wire or string with multiple beads strung (like an abacus) used for keeping score. Points "on the wire" are a type of handicap used, where a weaker player will be given a certain number of points before the start of the game.

(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).

In snooker, the highest-value colour ball on the table, being worth seven points. In some (especially American) snooker ball sets it is numbered "7" on its surface.
The black ball (usually numbered "8") in the eight-ball variant game blackball (and its variants); also the common British term for the slightly larger but otherwise identical 8 ball in a kelly pool set (a.k.a. American or WPA pool set).

Also bar rules, pub pool, tavern pool. Pool, almost always a variant of eight-ball, that is played by bar players on a bar table. Bar pool has rules that vary from region to region, sometimes even from venue to venue in the same city, especially in the U.S. Wise players thus ensure understanding of and agreement to the rules before engaging in a money game under bar rules. Typical differences between bar pool and tournament eight-ball are the lack of ball-in-hand after a foul, the elimination of a number of fouls, and (with numbered ball sets) the requirement that most aspects of a shot be called (including cushions and other object balls to be contacted) not just the target ball and pocket. Bar pool has evolved into this "nitpicky" version principally to make the games last longer, since bar pool is typically played on coin-operated tables that cost money per-game rather than per-hour. Competitive league pool played on bar tables, however, usually uses international, national or local/regional league rules, and is not what is usually meant by "bar pool".