Definition of cluster

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

24 Random Essential Billiards Terms

This refers to the cluster of balls remaining in a similar position to where they were within the break
Also spot-stroke, spot hazard. A form of nurse shot in English billiards, in which the red ball, which must be spotted to a specific location after every time it is potted before another shot is taken, is potted in such as way as to leave the cue ball in position to repeat the same shot, permitting a skilled player to rack up many points in a single break (series of shots in one visit).
An exhibition shot designed to impress either by a player's skill or knowledge of how to set the balls up and take advantage of the angles of the table; usually a combination of both. A trick shot may involve items otherwise never seen during the course of a game, such as bottles, baskets, etc., and even members of the audience being placed on or around the table.
Same as cue.
(Chiefly U.S.) Side spin (english) placed on a same side of the cue ball as the direction in which the object ball is being cut (left-hand english when cutting a ball to the left, and vice versa). In addition to affecting cue ball position, inside english can increase throw.
A short and loose stroke performed in a manner similar to the way one throws a dart; usually employed for a jump shot. See also nip draw.
This is a special shaped leather or plastic bottle that is used on the table during play in special pocket games.
In snooker, where the cue ball is resting in contact with another ball. If this ball is a ball that may legally be hit, then it is allowable to simply hit away from it and it counts as having hit it in the shot. If the ball moves, then a push shot must have occurred, in which case it is a foul.
Chiefly British. This is a shot in a snooker game where the first object ball hit contacts another object ball and the second one is pocketed. If both of the balls are red, or if the second ball would be on if the first ball had not been deemed free then it is an allowed shot.
A term used to indicate balls that are frozen, or close enough that no matter from which angle they are hit from the combination will send the outer ball the same direction. "Are the 2 and 7 pointing at the corner?? Okay, I'll use that duck to get position way over there."
Chiefly British: The rail at the Top of the table. Compare foot rail; contrast Bottom rail.
Same as cheating the pocket. Principally used in snooker.
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.
When the object ball lies behind another ball which makes it impossible to be struck by the cue with a direct hit.
As in many other sports, "legal" means not causing or likely to cause a foul (the opposite being illegal). A legal hit is one in which the requirements for a non-foul hit are met (e.g., in nine-ball, the lowest-numbered ball on the table was hit by the cue ball first, and at least one object ball was pocketed, or any ball reached a cushion, after the hit on the first object ball.). A legal shot is one in which no foul of any kind was involved (e.g. there was not a double hit by the cue, the player's bridge hand did not move a ball, etc.). A legal stroke is one in which the cue stroke obeyed the rules (e.g. the shooter did not perform an illegal jump shot by scooping under the cue ball with the cue tip). A legal ball is a ball-on, an object ball at which it is permissible for the player to shoot. And so on. The term can be used in many ways consistent with these examples ("legal pocket" in one-pocket, "legal equipment" under tournament specifications, etc.).
This is the way a ball rolls when impeded by something on the table or a blemish in the cloth, often times regular players will remember certain rolls and play to them.
In snooker and other British usages, a break of 50-99 points (100 points or more being called a century), which involves potting at least 12 consecutive balls (i.e. the last 3 reds with at least 2 blacks and a pink, followed by all the colours).
Balls remain unmoved after a player's shot.
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.
This is a particular ball which lends itself to be used as a "blocker" or a "protector."
To use a particular ball as security by playing a safety or leaving it where it will act as one.
0-2 Barbecue is a slang billiard term that refers to a single player loosing the first 2 matches in a double elimination tournament. This double loss results in that player being knocked out of the tournament without winning even one game.
This is the final object ball you need to pocket in order to win a game of one pocket.
A set of paired balls in the game of cribbage pool that have a number value which combined equal 15. For example, the 8 ball and the 7 ball added together equal 15 and thus constitute one cribbage if pocketed in succession.
Also slop shot. A luck shot. Compare fish, fluke and Lorengo; contrast mark and call. Also sloppy. Descriptive of any game where the rules have been varied to allow luck shots not normally allowed or where no foul rules apply.