Definition of cluster

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

24 Random Essential Billiards Terms

A set practice routine.
In British terminology, a bank shot.
Also semi-massé shot. A moderate curve imparted to the path of the cue ball by an elevated hit with use of english (side); or a shot using this technique. Also known as a curve (US) or swerve (UK) shot. Compare massé.
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.
Same as position. "She got good shape for the next shot". See also position play, leave.
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.
Same as cue.
A common aiming method in which a phantom ball is imagined frozen to the object ball at the point where an imaginary line drawn between their centers is aimed at the desired target; the cue ball may then be shot at the center of the "ghost" ball and, ideally, impact the object ball at the proper aiming contact point. The ghost ball method of aiming results in misses where adjustment is not made for collision induced throw.
Same as spot
A type of nurse shot used in English billiards in which two coloured balls are positioned on either side of the mouth of a snooker table pocket but not touching and, thus placed, can be successively contacted and scored off over and over by the cue ball without moving them.
Also last pocket. A common rule in informal bar pool, especially bar/pub eight-ball, in which the money ball must be pocketed (potted) in the same pocket as the shooter's last object ball (each player may be said to eventually "own" a pocket, for the duration of the game, in which their 8 ball shot must be played if they have already run out their suit). The variant is not extremely common in the United States or the UK, but is near-universal in much of Latin America (where two cue ball scratches are permitted when attempting the 8 ball shot and count as simple fouls, with only a third scratch constituting a loss of game). Last pocket is also common in North Africa. Last-pocket rules require careful position play, and frequently result in bank and kick shots at the 8 ball.
Describing a difficult pot: "the awkward cueing makes this shot missable."
Chiefly British: The rail at the Top of the table. Compare foot rail; contrast Bottom rail.
A game that basically cannot be lost based on disparity of skill levels; "this game is a lock for him."
The act of setting up the balls for a break shot. In tournament play this will be done by the referee, but in lower-level play, players either rack for themselves or for each other depending on convention.
A cross-corner bank shot from one end of the table to the other (i.e. across the center string). Long banks are considerably more difficult, because of the smaller margin for error due to distance and angle widening, than cross-side banks and short cross-corner banks from the same end of the table.
Hitting the object ball with too large of a cut angle; hitting the object ball too thin. It is a well-known maxim that overcutting is preferable to undercutting in many situations, as is more often leaves the table in a disadvantageous position on the miss than does an undercut. See also professional side of the pocket.
Chiefly British: Short for side spin. In Canadian usage, the term is sometimes used as a verb, "to side".
Sometimes called spots and stripes, stripes and solids or, more rarely, bigs and littles or highs and lows.
All fifteen numbered balls are used in a conventional triangle rack.
Each player is assigned either the solid balls (1-7) or the striped balls (9-15). The object is to pocket all of your assigned balls and then pocket the 8-ball.
Modification of the rules and/or scoring of a game to enable players of variable abilities to compete on a more even playing field. Examples of handicapping include spotting balls and giving games on the wire to an opponent. In league play, other forms of handicapping include awarding compensating points to a lesser-skilled team, or using numerical player ranking systems to adjust final scores between opponents of different skill levels.
This term refers to a low percentage one pocket shot.
A tournament format in which each contestant plays each of the other contestants at least once. In typical league team play, round robin format means that each member of the home team plays each member of the visiting team once. This format is used by BCAPL, VNEA and many other leagues.
Basic cue tip contact points on the cue ball to impart various forms of spin. Top spin is also known as follow, side spin as english, and bottom spin as back spin, draw or screw.Rotational motion applied to a ball, especially to the cue ball by the tip of the cue, although if the cue ball is itself rotating it will impart (opposite) spin (in a lesser amount) to a contacted object ball. Types of spin include top spin, bottom or back spin (also known as draw or screw), and left and right side spin, all with widely differing and vital effects. Collectively they are often referred to in American English as "english". See also massé.
Also littles, little ones, little balls. In eight-ball, to be shooting the solid suit (group) of balls (1 through 7); "you're little, remember", "you're the little balls" or "I've got the littles". Compare small, solids, reds, low, spots, dots, unders; contrast big.
A cue dedicated to jumping balls; usually shorter and lighter than a playing cue and having a wider, hard tip. Also referred to as a jump stick.