Definition of Open

Random method for pairing of opponents when setting up a bracket system for a tournament.

Failure to hit an object ball at all with the cue ball. In most sets of rules, this is a foul like any other. However, in some variants of bar pool a table scratch while shooting for the 8 ball is a loss of game where other more minor fouls might not be, as is scratching on the 8 ball (neither result in a loss of game in most professional rules).
By way of drift from the above definition, the term is also applied by many league players to the foul in more standardized rules of failing to drive a (any) ball to a cushion, or to pocket a legal object ball, after the cue ball's initial contact with an object ball.
By way of entirely different derivation ("scratch off the table"), it can also mean knocking the cue ball (or more loosely, any ball) completely off the table.

Principally British: In snooker, if a player wins a match without the need for the final session to be played (for example, if a player wins a best-of-25-frames match split into three sessions - two sessions of eight frames and one of nine - by a margin of say, 13 frames to 3), then they are said to have won the match "with a session to spare".

This is the portion of the cue you would be holding if there was no wrap or grip present. This is the position where the best gripping power can be generated, and is situated below the forearm and above the butt. This portion is often covered with a wrap, but other times left bare to create a simple seamless style.

Anything that causes a foul according to the rules of a game.

This refers to the cluster of balls remaining in a similar position to where they were within the break.

When playing 9 Ball, a dead ball is an object ball the falls into a pocket when a foul has been committed (for example, the shooter scratches or does not hit the lowest ball first). If keeping score by counting balls fallen, neither player gets the point for that ball.

The area on the table behind the head string.
The origin of the term has been the subject of some speculation but the best explanation known is that in the 1800s, many homes did not have room for both a billiard table and a dining room table. The solution was a billiards table that had a cover converting it into a dining table. Kept in the dining room, play on such a table was often restricted by the size of the room, so it would be placed so that the head rail would face the connected kitchen door, thus affording a player room for the backswing without hitting a wall. A player was therefore either half or sometimes fully (literally) "in the kitchen" when breaking the balls.

This is a style of playing a pool game with a partner playing on your team. You can either take turns or play in a tag team style. This works well when there are a lot of people around that want to play.
A form of team play in which two players compete against another team of two players in any given frame or match. In a doubles game, the first player from the breaking team is the only one who shoots during the opening inning, with control of the table passing to a member of the opposing team at the end of that inning, then upon the end of the opponent's inning to the doubles partner of the original player, and next to the second opponent, play proceeding in this doubly alternating manner until concluded. Contrast Scotch doubles.

The 5 out (meaning the player getting the handicap can win by making the 5, 6, 7, 8 or 9 balls).

Same as foot spot. Chiefly British today, but also an American usage ca. World War I.

A British term describing when a ball is tight on the cushion and a player sends the cue ball to hit both the object ball and the rail at nearly the same time; the object ball, ideally, stays tight to the rail and is thus "velcroed" to the rail. Inside english is often employed to achieve this effect, hitting slightly before the ball. The movement of a ball just next to the rail (but not the shot described to achieve this movement) is called hugging the rail in both the UK and the US.

A pool table where two shims have been placed on the sides of each pocket (in the jaws beneath the cloth), making the pockets "tighter" (smaller). Such tables are "tougher" than unshimmed or single-shimmed tables.

Competition between an individual player and an individual opponent, as opposed to team play such as scotch doubles and other multi-player variants.
A team play format in which an individual player from the home team plays a race against an individual player from the visiting team, and then is finished for that match. Several large leagues use this format, including APA/CPA and USAPL.

In certain carom billiards games, any shot in which the cue ball is sucessfully caromed off an object ball to strike another object ball (with or without contacting cushions in the interim) is a considered a billiards shot.

This is the ball that sits in the front, or apex, position in the rack.

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 tight, Spandex glove covering usually most or all of the thumb, index finger and middle finger, worn on the bridge hand as a more convenient and less messy alternative to using hand talc, and for the same purpose: a smooth-gliding stroke.

Australian: Defeated with all seven of one's object balls (in blackball or eight-ball) remaining on the table.

The table reserved for games played for money or the best table in the house. This table is always of better quality and regularly maintained. Money tables are most commonly reserved for big action.

The placement of the balls, especially the cue ball, relative to the next planned shot. Also known as shape.

Toward the head of the table. This is the playing area on the table above the middle pockets. The idea in an up table game is that shots are more difficult and further from the pockets in one pocket pool.

This is a shot in snooker where the cue ball follows a struck object into the pocket.

Also shortstop, short-stop. This is a player that is excellent at pool, but tends to fall short of number one. A shortstop is the best player relative to a particular scene. A second-tier professional who is not (yet) ready for World Championship competition. It can also be applied by extension to a player who is one of the best in a region but not quite good enough to consistently beat serious road players and tournament pros. The term was borrowed from baseball.