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 League, 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

A player of cue sports.
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.
To allow an opponent to stop playing a set for money in exchange for something. If a player is winning a set by a wide margin, with $100 on the line, the player could say, "I'll let you out now for $75." This is usually meant to save pride.
A three cushion billiards shot in which the cue ball first strikes two cushions before hitting the first object ball then hits a third cushion before hitting the second object ball. So called because the shot opens up like an umbrella after hitting the third rail. Umbrella shots may be classified as inside or outside depending on which side of the first object ball the cue ball contacts.
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.
This shot is a minimally calculated distressed shot which makes it evident to the opponent you no longer have any hope to winning the game.
Short for right english (side), i.e. side spin imparted to the cue ball by stroking it to the right-hand side of its vertical axis. Contrast left.
A player who during the course of a tournament does not lose focus. Typically said of those players that regularly make it to the finals of a tournament.
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.).
Feel generally refers to that elusive quality that makes one cue feel special or superior to another. In essence, it is the cumulative effect of all of a cues characteristics, including weight, shaft diameter, balance, grip material, length, etc. It can vary greatly from one player to another. A cue that feels great to one player does not necessarily fell good to another.
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.
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.
Same as break.
To play a shot with the stroke and speed that makes it easiest to pocket the object ball, even at the expense of sacrificing position.
A tournament format in which a player must lose two matches in order to be eliminated.
See two-shot carry.
Be in a game where either because of disparity in skill level, or because of a handicap given, it would be very difficult to lose.
The effect of shooting regulation-weight object balls with an old-fashioned over-weight bar table cue ball, such that the cue ball moves forward to occupy (sometimes only temporarily), or go beyond, the original position of the object ball, even on a draw or stop shot, because the mass of the cue ball exceeds that of the object ball. Players who understand smash-through well can use it intentionally for position play, such as to nudge other object balls nearby the target ball. Smash-through also makes it dangerous in bar pool (when equipped with such a cue ball) to pocket straight-on ducks with a stop shot instead of by cheating the pocket because of the likelihood of scratching the cue ball.
You can cheat the pocket by angling your shot to go in at the right or left of the pocket opening when sinking a shot. This permits the cue ball to strike the object ball at a different contact point than the most obvious one.
Chiefly British: The half of the table from which the break shot is taken. This usage is conceptually opposite that in North America, where this end of the table is called the head.
Three equally spaced diamonds are normally between each pocket on a pool table. On a carom table, the pockets themselves are replaced by additional diamonds. Diamonds get their name from the shape of the markings traditionally used; though many today are round, square, etc., these rail markings are still referred to as "diamonds".
Two or more object balls that are touching or are close together.
Any shot where the cue ball is intentionally jumped into the air to clear an obstacle
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.