Definition of session

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.

24 Random Essential Billiards Terms

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.
Skilled playing in which knowledge of ball speed, angles, post-impact trajectory, and other factors are used to gain position (i.e. a good leave) after the target ball is struck. The goals of position play are generally to ensure that the next shot is easy or at least makeable, and/or to play a safety in the advent of a miss (intentional or otherwise).
Carambole billiards is a French billiards game involving two cue balls and a single red object ball. The purpose of carambole billiards is to obtain points by contacting the object ball and the opponent's cue ball in the same shot.
A foul where the rules are blatantly, intentionally violated, with a stiffer penalty (e.g., loss of game) than normal.
A type of safety shot in the middle of a safety exchange that is not intended to put the opponent in a difficult situation regarding their next safety, but rather played so as to not leave an easy pot on. A typical example in snooker, which sees the most shots of this kind, is a slow roll-up into the pack.
This is a creative game played between four players, using hands instead of cue sticks. The goal is to shoot as many balls as possible into the diagonally opposing corner pocket you are standing behind. The shooting is done taking turns and rotating counter clockwise. When misses on the pocket occur, the ball is open game to be stolen and pocketed in the new opposing pocket during the new owners turn. Ties are decided by lagging with the hands, and the winner of one game is the first to shoot in the next.
A predetermined, fixed number of games players must win to win a match; "a race to seven" means whomever wins seven games first wins the match.
A geometric form, usually aluminum, wooden or plastic, used to assist in setting up balls in games like eight-ball, nine-ball, and snooker. The rack allows for more consistently tight grouping of balls, which is necessary for a successful break shot. In most games a triangle-shaped rack capable of holding fifteen balls can be employed, even if the game calls for racking less than a full ball set, such as in the game of nine-ball. For further information, see the Rack (billiards) main article.
In some games, refers to a single frame.
In snooker, a situation during a frame in which the first line of the remaining reds grouped together, where the original pack was, are in a straight horizontal line. This has implications when opening the pack, as a full-ball contact off the top cushion will usually cause the cue-ball to stick to the red and fail to develop a potting opportunity.
When the cue ball contacts three or more cushions in carom games.
Describes a ball rolling along a rail in contact or near contact with it, or which makes multiple successive contacts with the rail.
In snooker, to leave the cue ball ball on the spot of a colour ball after potting it. This is usually performed where re-spotting of the colour ball would cause positional problems for the player, such as blocking available pots on one or more red balls.
Describes a cue ball sliding on the cloth without any top spin or back spin on it.
This is a kind of cue made of only two pieces of wood, and joined together using an advanced adhesive along the points of the cue. This connection gives the cue a flawless look and a fluid feel when shooting.
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."
This is the portion of the joint that actually connects the two sides of the cue, often called the pin or male end. This comes in a number of different sizes and shapes which some believe has an influence on the hit of the cue stick.
This is a blemish added to the table in order to help execute a shot; these marks are not allowed and result in a foul.
Anything that causes a foul according to the rules of a game.
Describes tightly woven and well-used (but clean) billiard table cloth (baize), upon which the balls move quickly and roll farther, as they experience less friction than with fuzzy or dirty cloth. May be used more extendedly, as in "this is a really fast table". Fast cloth makes draw (screw) shots somewhat less effective, as there is less purchase for the cue ball's back spin. By the same token, slide and stop shots are easier on fast cloth because it is so comparatively smooth.
Asian Pocket Billiard Union. The APBU is a member of the WPA.
This refers to the distance of deflection that the ball comes off of the cue stick after a hit is applied with side spin on it.
The ACS Canadian affiliate organization, the Canadian Cue Sport Association.
This is a term used to refer to all the different aspects involved in setting up a shot, i.e. the stance, grip, bridge, and stoke.
This is the way your hand is configured to support the shaft of the cue during a shot.