Definition of open

In eight-ball, when all object balls are balls-on for either player.
A description of a break shot in which the rack (pack) is spread apart well. See also the open break requirement in some games' rules, including eight-ball and nine-ball.
In carom billiards, descriptive of play in which the balls are not gathered.

24 Random Essential Billiards Terms

In eight-ball and related games, describes the situation in which neither player has yet claimed a suit (group) of balls. Often shortened to simply open: "Is it still an open table?" "Yes, it's open."
A term applied especially in snooker for a type of double off three cushions, e.g. around the baulk colours and into a centre pocket. Such a shot is very difficult to make and would not normally be played as anything more than a shot for nothing.
This is when you strike a cue ball off center to gain control on the movement on the cue ball.
This is a shot where the cue ball contacts an object ball and moves it along a path, but because the cue ball is still in motion it re-contacts the object ball and pushes it in the pocket after it stops.
Chiefly American: The cushion on the foot rail. Compare top cushion; contrast head cushion.
This refers to a shot that travels on a shallower path due to the english placed on it. This is to come up on the near side of a pocket on a bank shot.
Also known as 14.1 continuous pool. This game is played on a pocketed table with the fifteen object balls and a cue ball. Every shot must begin with a call, and if made, you get to continue calling shots. The idea is to reach a predetermined score before your opponent. When all but one ball remains, the rack is started over without the apex ball in position, and the last shot is called in such a way as to break the new rack and continue play.
The heavy, finely milled rock (slate) that forms the bed of the table, beneath the cloth. Major slate suppliers for the billiards industry are Italy, Brazil and China. Some cheaper tables, and novelty tables designed for outdoor use, do not use genuine slate beds, but artificial materials such as Slatrol.
The placement of the balls, especially the cue ball, relative to the next planned shot. Also known as shape.
The person in charge of the game whose primary role is to ensure adherence by both players to the appropriate rules of the game being played. Other duties of the referee include racking each frame, re-spotting balls during the course of a game, maintaining the equipment associated with the table (e.g. keeping the balls clean), controlling the crowd and, if necessary, controlling the players. Formerly sometimes referred to as the umpire.
A shot in which the cue ball is driven first to one or more rails, then hits an object ball and kisses back to the last rail contacted. It is a common shot in carom games, but can be applied to such an instance in any relevant cue sport.
Also treble. A British term for a type of bank shot in which the object ball is potted off two cushions, especially by sending it twice across the table and into a side pocket. Also called a two-cushion double.
A foul where the rules are blatantly, intentionally violated, with a stiffer penalty (e.g., loss of game) than normal.
A bank shot that follows a Z shaped pattern as it bounces off of two rails.
Slang for the cue ball.
Describes a ball rolling along a rail in contact or near contact with it, or which makes multiple successive contacts with the rail.
Also highs, high balls, high ones. In eight-ball and related games, to be shooting the striped suit (group) of balls (9 through 15); "you're high balls" or "I've got the highs" ("you're high" is rare, because of the "intoxication" ambiguity). Compare stripes, yellows, big ones, overs; contrast low.
Short for right english (side), i.e. side spin imparted to the cue ball by stroking it to the right-hand side of its vertical axis. Contrast left.
To intentionally lose a game, e.g. to disguise one's actual playing ability. An extreme form of sandbagging. See also hustle. See also Match fixing for the synonym "tank", used in sports more generally.
In snooker, the cushion opposite the top cushion and bounded by the yellow and green pockets (i.e. same as bottom cushion).
To play even; without a handicap. Also called heads up.
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.
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 fast paced offensive game similar to 9-ball but only using balls numbered 1 through 7.
Pocketing the 7-ball wins the game. Under the current pro rules of 7-ball, any missed shot gives your opponent ball-in-hand.