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

This is any game of pool played with money on the line. You can "put some action" on the game.
The situation arising in many pool games where a ball is spotted to the table's foot spot or some other specific location and the cue ball must be shot from the kitchen or the "D". There are diamond system aiming techniques for pocketing such shots without scratching the cue ball into a pocket.
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.
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.
Slang for the cue ball.
A game that basically cannot be lost based on disparity of skill levels; "this game is a lock for him."
This is a method of handicapping that designates a wild ball for a lesser player to be able to pocket at any point during a game in order to win.
Chiefly American: The short rail at the foot of the table. Frequently used imprecisely, to mean foot cushion. Compare top rail; contrast head rail.
In snooker, the colour ball that is worth three points, being the second-least valuable colour behind the yellow. It is one of the baulk colours.
This is the playing surface for billiards games. Consisting of 6 pockets, cushions on the side, and a felt layer covering the hard table portion, the length is usually twice as long as it is wide, but varies depending on the game at hand.
Same as mechanical bridge; so-called because of its typical shape.
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.
In pool, the degree to which racked balls move apart upon impact by the cue ball as a result of a break shot.
In snooker, a shot sending the cue ball into the pack of red balls and separating them (after potting the ball-on). At least one split is usually necessary in each frame, since the original triangle of reds does not allow any balls to be potted reliably.
Also shortstop, short-stop. This is a player that is excellent at pool, but tends to fall short of number one. A shortstop is the best player relative to a particular scene. A second-tier professional who is not (yet) ready for World Championship competition. It can also be applied by extension to a player who is one of the best in a region but not quite good enough to consistently beat serious road players and tournament pros. The term was borrowed from baseball.
Having the cue ball stop precisely where intended.
Having the cue ball stop at or near the center of the table on a forceful break shot (the breaking ideal in many games such as nine-ball);
This is an object sometimes placed underneath the cue tip.
Also double-century break. In English billiards, a break of 200-299 points (i.e. double a century). Larger multi-centuries are regularly achieved. Rare in amateur play, triple centuries are routine, and quadruples not uncommon at World Professional Billiards Championships; 2007 winner Mike Russell shot four triples in the final round alone, while of sixteen competitors, three shot quadruple centuries (one once, one twice, and Russell three times). Quintuple centuries are rare even at the professional level, with only the 494 shot by nine-time World Champion Russell (who has more such titles than any other player in history as of 2007) coming close in that event. World Champion Geet Sethi holds the world record, at a duodectuple century (and then some) of 1276 consecutive points."
A multi-game division of a match, as used in some league and tournament formats. For example, in a match between 2 teams of 5 players each, a 25-game match might be divided into 5 rounds of 5 games each, in which the roster of one team moves one line down at the beginning of each round, such that by the end of the match every player on team A has played every player on team B in round robin fashion.
A level of competition elimination in a tournament, such as the quarterfinal round, semifinal round and final round.
Sometimes called a snake shot. A carom billiards shot, common in three-cushion billiards, where the cue ball is shot with reverse english at a relatively shallow angle down the rail, and spins backwards off the adjacent rail back into the first rail.
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 to direct the cue ball by barely contacting an object ball.
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.
This is to take all the money from a player or to have lost all of your own money.
Also highs, high balls, high ones. In eight-ball and related games, to be shooting the striped suit (group) of balls (9 through 15); "you're high balls" or "I've got the highs" ("you're high" is rare, because of the "intoxication" ambiguity). Compare stripes, yellows, big ones, overs; contrast low.