Definition of round

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.

24 Random Essential Billiards Terms

To sink a ball into a pocket.
Asian Pocket Billiard Union. The APBU is a member of the WPA.

1 - This is a shot in snooker where the cue ball follows a struck object into the pocket.

2- This is the male end of the joint located at the base of the shaft. This threaded piece, usually made of metal, connects the shaft with the forearm. The length, width, pitch and depth of threading of the pins vary from joint to joint, but most offer you a flat-faced wood-to-wood connection with the collar. This type of connection will deliver a softer hit. For a harder hit, some pins have a protruding tip without threads that directs the shaft concentrically with a pin that is buried in the collar at the joint. If you want to keep the pin of your shaft safe when your cue is dismantled, it is easy and important to use a joint protector that simply screws over your pin.

A tournament format in which a player is out of the tournament after a single match loss.
Powdered chalk housed in a cube. This chalk is rubbed into the tip of your cue to help with grip between the tip of the cue and the cue ball. This is more important to use if you are using a medium or hard tip, as opposed to a soft tip, which already provides some good grip. As a warning when purchasing a type of chalk, there is much debate over which chalk offers the best friction, so you best do your research!
One of the alternating turns players (or doubles teams) are allowed at the table, before a shot is played that concedes a visit to his/her opponent (e.g. "he ran out in one visit"). Usually synonymous with inning as applied to a single player/team, except in scotch doubles format.
Verb: "To Clock" To carefully note the abilities or betting inclinations of other players for future reference.
Area on the corner of a carom table, which is defined by a line between the second diamond on the side rail and the first diamond on the end rail, where only three successive points are allowed before the object ball must be cleared out of the area.
A player who was playing very well but suddenly starts playing badly. e.g. "He was making everything on every shot, then lost his stroke and couldn't hit anything, costing him the match."
To shoot without taking enough warm-up strokes to properly aim and feel out the stroke and speed to be applied. One-stroking is a common symptom of nervousness and a source of missed shots and failed position.
This is a tip tool for cleaning the edges of you tip after mushrooming occurs.
The angle at which a ball approaches a rail, as measured from the perpendicular to the rail.
Four-ball is a carom billiards game. The game is played on a pocketless table with four balls, usually one light red, one dark red, and two whites (or just two reds and two whites). Each player is assigned one of the white balls as his own cue ball. A point is scored when a shooter caroms on any two other balls. Two points are scored when the player caroms on each of the three other balls.
See overcut.
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 is a style of playing a pool game with a partner playing on your team. You can either take turns or play in a tag team style. This works well when there are a lot of people around that want to play.
A form of team play in which two players compete against another team of two players in any given frame or match. In a doubles game, the first player from the breaking team is the only one who shoots during the opening inning, with control of the table passing to a member of the opposing team at the end of that inning, then upon the end of the opponent's inning to the doubles partner of the original player, and next to the second opponent, play proceeding in this doubly alternating manner until concluded. Contrast Scotch doubles.
Used by itself often with "low" and "high": "that's a low-percentage shot for me", "I should really take the high-percentage one".
This is the red colored object ball in carom games.
In snooker, any of the 15 balls worth 1 point each that can be potted in any order. During the course of a break a player must first pot a red followed by a colour, and then a red and colour, etc., until the reds run out and then the re-spotted six colours must be cleared in their order. Potting more than one red in a single shot is not a foul - the player simply gets a point for each red potted.
In blackball, one of two groups of seven object balls that must be potted before the black. Reds are spotted before yellows, if balls from both group must be spotted at the same time. Compare stripes; contrast yellow ball.
In carom billiards, the object ball that is neither player's cue ball.
This is the final object ball you need to pocket in order to win a game of one pocket.
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).
Slang for a mechanical bridge.

1- Shortened phrase of "ball-in-hand".

2 - In snooker, the ability to place the cue ball anywhere inside the boundaries of the D. This occurs at the start of a frame, and after the cue ball has been potted or forced off the table.
Also a short form of "Ball In Hand".

Describing a shot which requires one or more balls to be played off several cushions, such as an elaborate escape or a positional shot; "he'll have to send the cue ball round the angles to get good position."
Netted or cupped pockets that do not return the balls to the foot end of the table by means of a gutter system or sloped surface beneath (they must instead be retrieved manually).