Definition of Head rail

The wrap is situated over the handle of the cue, below the forearm and above the butt. Common materials used are Irish linen, leather, or cork. These materials make sense, because they provide a sure grip, long life, and help to absorb moisture from the hand when you are sweating through a difficult rack. In addition, wraps are used to compliment the color or style of the cue stick and to elegantly complete the look.

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.

Chiefly Australian: Same as a force follow shot.

This is a timing device for monitoring and restricting shot times for a player.

This is the imaginary line that a ball would need to follow in order for it to result in an effective bank shot.

Either of the balls on the lateral extremities of a racked set of balls in position for a break shot; the two balls at the outside of a 15-ball rack in the back row, or the balls to the left and right of the 9 ball in nine-ball's diamond rack-shaped opening set up position. In nine-ball It is seen as a reliable sign of a good break (which is normally taken from close to either cushion in the kitchen) if the opposite wing ball is pocketed.

In eight-ball and related games, describes the situation in which neither player has yet claimed a suit (group) of balls. Often shortened to simply open: "Is it still an open table?" "Yes, it's open."

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 and CPA Leagues, 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.

A line, sometimes imaginary (especially in American pool), sometimes drawn on the cloth, that runs horizontally across the table from the second diamond (from the head rail) on one long rail to the corresponding second diamond on the other long rail. In most pool games, the opening break shot must be performed with the center (base) of the cue ball behind the head string (i.e. between the head string and head rail). The head string intersects the long string at the head spot, and delimits the kitchen (and, in European nine-ball, the outer boundary of the break box). The head string's position is always determined by the diamonds, in contrast to the similar but different baulk line, the position of which is determined by measurement from the bottom cushion (head cushion).

Either of the two shorter rails on a standard pool, billiards or snooker table. Contrast side rail/long rail.

Displacement of the cue ball's path away from the parallel line formed by the cue stick's direction of travel; occurs every time english is employed. The degree of deflection increases as the amount of english applied increases. It is also called squirt, typically in the United States.

Also known as 14.1 continuous pool. This game is played on a pocketed table with the fifteen object balls and a cue ball. Every shot must begin with a call, and if made, you get to continue calling shots. The idea is to reach a predetermined score before your opponent. When all but one ball remains, the rack is started over without the apex ball in position, and the last shot is called in such a way as to break the new rack and continue play.

Also known as Free-stroking. This is slang for when a player begins to play untroubled and relaxed because they have built up a substantial lead.

The act of playing a devastating safety which leaves the opponent in a situation where it is very difficult or near impossible to make a legal hit on an object ball

A description of play in carom billiards games in which the balls remain widely separated rather than gathered, requiring much more skill to score points and making nurse shots effectively impossible, and making for a more interesting game for onlookers. Most skilled players try to gather the balls as quickly as possible to increase their chances of continuing to score in a long run.

A very thin cut shot in which the cue ball just brushes the edge of an object ball. "Feather" by itself can be both noun and verb (e.g. "feathering the ball").

A pool room may refer to an establishment that is the same as a pool hall. A private residence may also have a pool room. That would be a room in a house or a recreation room in an apartment building, hotel or condominium complex that has a room that the main activity is dedicated to playing pool.

To sink a ball into a pocket.

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.

A denigrating slang term for the mechanical bridge.

A shot, especially common in straight pool and in some variants of blackball (but not WEPF/EPA rules), in which a player intentionally commits a foul with the object in mind of either leaving the opponent with little chance of running out or simply to avoid shooting where no good shot is presented and to do anything else would give the opponent an advantage. It is often referred to in straight pool as a "back scratch."

Also goose neck rest. Same as swan.

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.

Also known as a "power draw", means applying very powerful draw on the cue ball thereby causing the maximum amount of draw.