Definition of black ball

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).

24 Random Essential Billiards Terms

In pool, the degree to which racked balls move apart upon impact by the cue ball as a result of a break shot.
In snooker, a shot sending the cue ball into the pack of red balls and separating them (after potting the ball-on). At least one split is usually necessary in each frame, since the original triangle of reds does not allow any balls to be potted reliably.
An upright pin, which looks like a miniature bowling pin, cone or obelisk. Skittles, as employed in billiards games, have been so-called since at least 1634. One standardized size, for the largely Italian and South American game five-pins, is 25 mm (1 in.) tall, with 7 mm (0.28 in.) round bases, though larger variants have long existed for other games such as Danish pin billiards. Depending upon the game there may be one skittle, or several, and they may be targets to hit (often via a carom) or obstacles to avoid, usually the former. They are also sometimes called pins, though that term can be ambiguous. Because of the increasing international popularity of the Italian game five-pins), they are sometimes also known even in English by their Italian name, birilli (singular birillo). Skittles are also used as obstacles in some artistic billiards shots. #Flat, thin rectangular skittles, somewhat like large dominoes, approximately 6 in. tall by 3 in. wide, and placed upright like an obelisks on the table in specific spots, are used in the obsolescent and principally Australian games devil's pool and victory billiards. Depending upon the exact game being played, there may be one pin, or several of various colors (e.g. ten white and two black in devil's pool), and they may be targets or obstacles, most commonly the latter. They are usually made of plastic, and are increasingly difficult to obtain, even from Australian billiards suppliers. A black obelisk skittle of this sort features prominently, as a particularly dire hazard, in several scenes of sci-fi/pool film Hard Knuckle (1992, Australia). Skittles as used in billiards games date to ground billiards (13th century or earlier) played with a mace, and hand-thrown games of bowls from at least the same era using the same equipment. Ball games using a recognizable form of skittle are known from as early as ca. 3300 BCE in Ancient Egypt.
A 7 inch (17.8 cm) square box drawn on a balkline table from the termination of a balkline with the rail, thus defining a restricted space in which only 3 points may be scored before one ball must be driven from the area. It developed to curtail the effectiveness of the chuck nurse, which in turn had been invented to thwart the effectiveness of the Parker's box in stopping long, repetitive runs using the anchor nurse.
A ball that is easily made from many positions on the table but which is left untouched while the rack is played, so that in the event the player gets out of position, the shooter has an insurance shot. Typically an insurance ball will be in or near the jaws of a pocket.
An imaginary line running horizontally across a billiards table from the second diamond (from the foot end of the table) on one long rail to the corresponding second diamond on the other long rail. The foot string intersects the long string at the foot spot. It is rarely drawn on the table.
When you hit the object ball you are aiming for (or the manditory next ball) without the cue ball hitting other object balls first.
Short for left english (side), i.e. spin imparted to the cue ball by stroking it to the lefthand side of its vertical axis. Contrast right.
Principally US: One or more sets, usually in the context of gambling. See also ahead race (a.k.a. ahead session) for a more specialized usage.
Principally British: Any of a group of pre-determined frames played in a match too long to be completed within a single day's play. A best of 19 frame match, for example, is generally played with two "sessions", the first composed of nine frames, the second of ten. This term is generally used only in the context of professional snooker, as matches at the amateur level are rarely played over more than nine frames. Longer matches can be split into three or four sessions.
In the APA and CPA Leagues, session refers to the season in which League play took place. There are three sessions in each League Year-Summer Session, Fall Session and Spring Session.
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.
This is an imaginary line that separates the halves of the table by crossing at the middle of the side of pockets.
This is a special shaped leather or plastic bottle that is used on the table during play in special pocket games.
Random method for pairing of opponents when setting up a bracket system for a tournament.
In snooker, the colour ball that is worth three points, being the second-least valuable colour behind the yellow. It is one of the baulk colours.
Also pro side of the pocket and missing on the professional (or pro) side of the pocket. Sometimes "of the pocket" is left off the phrase. To err on the side of overcutting a difficult corner pocket cut shot rather than undercutting in nine ball; "missing on the professional side of the pocket." So called because experienced players understand that on a thin cut, overcutting the object ball to a corner pocket will far more often leave the object ball in an unfavorable position for the incoming opponent than will an undercut, which often leaves the object ball sitting in front of or nearby the pocket it had been intended for on a miss. By contrast, in eight-ball, except when both players are shooting at the 8 ball, the incoming player after a miss is shooting for different object balls, so this maxim does not apply, and the opposite may be good strategy as, if the object ball stays near the pocket through an undercut, it is advantageously positioned for a subsequent turn and may block the opponent's use of the pocket.
A stroking technique in which a player releases his gripping hand briefly and re-grasps the cue farther back on the butt just before hitting the cue ball.
This is to win a game by pocketing enough balls before you opponent.
To contact the chosen object ball in such a way to make it bank off a rail before being pocketed.
This is the imaginary line that a ball would need to follow in order for it to result in an effective bank shot.
To allow an opponent to stop playing a set for money in exchange for something. If a player is winning a set by a wide margin, with $100 on the line, the player could say, "I'll let you out now for $75." This is usually meant to save pride.
Same as mechanical bridge; so-called because of its typical shape.
A type of nurse used in carom billiards games. With one object ball frozen to a cushion and the second object ball just slightly away from the rail, the cue ball is gently rebounded across the face of both balls, freezing the away ball to the rail and moving the frozen ball away the same distance its partner was previously, resulting in an identical but reversed configuration, in position to be struck again by the cue ball from the opposite side.
Also double-century break. In English billiards, a break of 200-299 points (i.e. double a century). Larger multi-centuries are regularly achieved. Rare in amateur play, triple centuries are routine, and quadruples not uncommon at World Professional Billiards Championships; 2007 winner Mike Russell shot four triples in the final round alone, while of sixteen competitors, three shot quadruple centuries (one once, one twice, and Russell three times). Quintuple centuries are rare even at the professional level, with only the 494 shot by nine-time World Champion Russell (who has more such titles than any other player in history as of 2007) coming close in that event. World Champion Geet Sethi holds the world record, at a duodectuple century (and then some) of 1276 consecutive points."
A rare and very difficult trick jump shot that turns into a draw shot upon landing. Requires precise application of spin in addition to the precise application of ball pressure to effectuate the jump. Jump draws are fairly often seen in professional trick shot competition.
The rules played in a particular venue not necessarily in comportment with official rules, or with common local bar pool custom.