Definition of cluster

Two or more object balls that are touching or are close together.

24 Random Essential Billiards Terms

This is when a player has scratched and the foul in one pocket calls for them to spot a ball, but not able to be spotted at the time. In this case a coin is usually placed on the side of the table to keep tabs.
The BCA Pool League is one of the major amateur pool leagues in the United States and is present in over a dozen other countries outside the U.S., with a significant presence in Canada
This technique works to keep your shot aligned by eyeing your shot above the table, and then locking your chin into position as you lower down to take your shot.
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.
This is a bank shot that goes off of the head rail and then straight to the pocket at the other end of the table.
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 League, 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.
Used when describing perfect play. "as if the balls had strings on them"
A set practice routine.
In British terminology, a bank shot.
A natural is an easy shot requiring no side spin. A shot is said to be natural if it does not require adjustments, such as a cut angle, side spin, or unusual force. A natural bank shot, for example, is one in which simply shooting straight into the object ball at medium speed and with no spin will send the object ball directly into the target pocket on the other side of the table.
Any shot where the cue ball is intentionally jumped into the air to clear an obstacle
This is to watch a match with such intensity that there is worry, usually because of a wager on the game.
When a player is on the receiving end of a devastating safety where it is very difficult or near impossible to make a legal hit on an object ball.
In snooker, the pocket nearest the yellow spot.
A player's (or doubles team's) turn at the table, usually ending with a failure to score a point or to pocket a ball, depending on the game, a foul, a safety or with a win. In some games, such as five-pins and killer, a player's inning is always limited to one shot, regardless of the intent and result of the shot. Usually synonymous with visit, except in scotch doubles format. The term is sometimes used to mean both players'/teams' visits combined, e.g. when referring to which inning in which a memorable shot occurred.
Named after their innovator, legendary cuemaker George Balabushka, Bushka rings are decorative bands of material incorporated into pool cues, commonly just above the wrap area, in the form of ebony and ivory blocks, or sometimes other materials, alternating in a checked pattern.
This is the running score of a player during his inning of play. The sum of the continuously scored points, or where the player stands in the run on the table.
The desired angle that must be created between the path of the cue ball and the path of the object ball upon contact to pot the object ball. It is usually measured to the center of the pocket. See also aiming line.
This is a shot where the cue ball double kisses in order to direct the object ball toward the pocket.
A thin sheet of rigid material in the size and shape of a physical ball rack (e.g. a diamond for nine-ball), with holes drilled though it, which is used to make permanent divots in the cloth of the table, one at a time for each ball in the racking pattern, by placing a ball in one of the holes in the carefully placed template and tapping it sharply from above to create the cloth indentation. The holes are spaced slightly closer than the regulation ball width of 21/2 inch (57.15 mm) apart, so that when the balls settle partially into their divots, the outer sides of these indentations create ball-on-ball pressure, pushing the balls together tightly. The purpose of the template is to do away with using a physical rack, with racking instead being performed simply by placing the balls into position, and the divots aligning them into the tightest possible formation automatically. This prevents accidental loose racks, and also thwarts the possibility of cheating by carefully manipulating the ball positions while racking. The European Pocket Billiard Federation (EPBF, Europe's WPA affiliate organization) has adopted this racking technique for its professional Euro-Tour event series.
Any standard pool cue used to shoot the majority of shots in a match.
This is a shot where the cue ball caroms off a number of balls in a pin ball, back and forth, fashion to achieve a shot.
This is what is brought to the table if you are playing at your best potential.
A foul where the rules are blatantly, intentionally violated, with a stiffer penalty (e.g., loss of game) than normal.
This is the International Billiards and Snooker Federation. This organization governs non-professional snooker and billiards play all over the world.