Definition of cluster

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

24 Random Essential Billiards Terms

Also on the lemon. Disguising the level of one's ability to play.
This is a location where a player can go inexpensively to refine their pool skills. These establishments began as horserace betting houses, and are still often filled with games involving money action. If you get thirsty, many pool halls offer cold refreshments, however, be careful you are not there just for the refreshments. In that case, you may as well be playing at a bar with a bent cue on a rain table.
The 'Lady Jane Grey' is a rarely used term to describe a shot in the game of snooker. The cue ball is baulk side of the spotted black after potting a red ball. The black is powerfully potted into a top corner pocket and the cue ball bounces off the top cushion into the red balls, moving them into space, thus allowing the continuation of a break. Named after Lady Jane Grey, the 16th Century Queen of England, possibly because the speed the cue ball must be hit matches the speed with which she was deposed from the throne.
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".
The tip of your cue is the smallest but most important piece on all of the stick. Ranging between 12 mm and 14 mm depending on the taper of you shaft, the average and most common tip size is 13 mm. The tip is usually made from treated and compressed leather and is attached at the top of your cue by screw or glue to the ferrule. There are variances in cue tip resistance from soft to hard. The softer offering more chalk retention, and the harder offering more longevity and power transferred through your shot (the hardest, phenolic tips are often used on the break). Because the surface of the tip is beveled it offers you control on the spin and direction of the cue ball in your shot. To keep this control, it is important to scuff up the surface of your cue a little so as to enhance the chalk retention potential. In addition to keeping you tip chalked, you want avoid it mushrooming over the ends of the ferrule after too many impacts without refinement. To much use, and not enough care with proper tools can hinder your ability to master the control from your cue tip to your shot.
A rack in the form of an equilateral triangle. There are different sizes of triangles for racking different games (which use different ball sizes and numbers of balls), including the fifteen ball racks for snooker and various pool games such as eight-ball and blackball. A larger triangle is used for the twenty-one ball rack for baseball pocket billiards). The smallest triangle rack is employed in three-ball (see illustration at that article) but is not strictly necessary, as the front of a larger rack can be used, or the balls can be arranged by hand.
The object balls in triangular formation, before the break shot, after being racked. See also pyramid.
Deviation of a ball from its initial direction of travel. Often the result of a poor-quality table and may be an artifact of the cloth, the bed, a ball with uneven weight distribution, or simply the floor the table stands on being uneven.
Descriptive of any game in which the object balls must be struck in numerical order. Billiard researcher Mike Shamos observes that it would be more intuitive to call such games "'series' or 'sequence'". The term actually derives from the set-up of the game Chicago, in which the balls are not racked, but placed numerically around the table along the cushions (and must to be shot in ascending order). Other common rotation games include pool (obviously), nine-ball, seven-ball, ten-ball.

1- This is a knowledgeable shot showing skill on the movement of the cue ball.

2- This is an experienced one pocket pool player that shows extraordinary skill at coordinating the cue balls and object balls for safety plays.

An imaginary line dividing the table into two equal halves lengthwise. It intersects the head string, center string and foot string at the head spot, center spot and foot spot, respectively.
A misnomer for hand talc.
With draw, as in "I shot that low left", meaning "I shot that with draw and with left english". Derives from the fact that one must hit the cue ball below it's equator, i.e. "low" on the ball, to impart draw. Contrast high.
American CueSports Alliance. Their mission statement is "To heighten the interest and awareness of cue sports through the support and sanctioning of organized competition throughout the United States and North America."

1.In pool games such as nine-ball, a specific handicap given (e.g., "what spot will you give me?").
2.In snooker, any of the six designated points on the table on which a colour ball is replaced after it has left the playing surface (usually after it has been potted).
3.An (often unmarked) point on the table, at the intersection of two strings. See foot spot, head spot, center spot for examples.
4.In UK eight ball, (when not playing with a reds-and-yellows colour ball set) any of the group of seven balls, other than the 8, that are a solid colour with just a circled number on the surface. In the US, these balls are usually referred to as solids or more colloquially as lows, littles or smalls, while British terms include dots and unders. Contrast stripes.
5.Alternate name for a table's diamonds.

1.In pool, return an illegally pocketed object ball to the table by placement on the foot spot or as near to it as possible without moving other balls (in ways that may differ from ruleset to ruleset).
2.In snooker, to return a colour ball to its designated spot on the table. Also called re-spot.
3.In nine-ball, the giving of a handicap to the opponent where they can also win by making a ball or balls other than the 9 ball (e.g. "she spotted me the seven ball").
4.In eight-ball, one-pocket and straight pool, the giving of a handicap to the opponent where they have to make fewer balls than their opponent does.
5.In some variants of pool, to place the cue ball on the head spot or as near to it as possible inside the kitchen/baulk, after the opponent has scratched.

Also string off. Chiefly British; Obsolete: Same as string or lag.
When a particular ball is given as a handicap in nine-ball, designating that ball in turn means that it must be made in rotation, when it is the lowest numerical ball remaining on the table, and cannot be made to garner a win earlier in the game by way of a combination, carom or any other shot. For example, if a player is spotted the 8 ball, he only wins by making that ball after balls 1 through 7 have been cleared from the table.
Also spider rest. A type of rest, similar to a common American-style rake bridge but with longer legs supporting the head so that the cue is higher and can reach over and around an obstructing ball to reach the cue ball. See also swan.
This is when you aim at one particular object ball that is not meant to go in the pocket, but is instead meant to contact another object ball which will continue the combination process or be pocketed.
Same as suit, predominantly in British terminology, i.e., in eight-ball either of the set of seven balls (reds or yellows) that must be cleared before potting the black. Generally used in the generic, especially in rulesets or articles, rather than colloquially by players.
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.

1- Pocketing of the cue ball in pocket billiards. In most games, a scratch is a type of foul. "Scratch" is sometimes used to refer to all types of fouls.

2- British term/slang for Draw

A player's auction at a pool tournament. Each player is called and players and spectators bid on the player. The highest bidder(s) pays their bid to the calcutta, and by doing so invest in that player's success. If a player wins or places in the tournament, those who "bought" the player receive a percentage of the total calcutta payout, usually tracking the percentage payout of the tournament prize fund. Typically, players have the option of purchasing half of themselves when the high bid is won by a third party. Like english and scotch doubles, usually not capitalized.
This is what is brought to the table if you are playing at your best potential.
This is when you strike a cue ball off center to gain control on the movement on the cue ball.