Definition of Defensive play

Usually a one-piece cue freely available for use by patrons in bars and pool halls.

A British term for someone with little experience or understanding of the game, who may be skilled at potting individual balls but does not consider tactics such as position or safety; "he's a potter not a player." See also banger.

A style of game play in which as many players are allowed to join as the participants choose, and anyone can quit at any time. The term, most often used in the context of gambling, is borrowed from poker. The folk games three-ball and killer are usually played as open ring games, as is Kelly pool.
By extension, a multi-player game that anyone may initially join, but which has a fixed roster of competitors once it begins, is sometimes also called a ring game. Cutthroat is, by its nature, such a game. A famous regular ring game event of this sort is the Grady Mathews-hosted six-player, $3000-buy-in ring ten-ball competition at the annual Derby City Classic.
A nine-ball ring game is played by more than two players. Safeties are not allowed.

A ball hanging over the edge of a pocket.

A pocket; usually used in disgust when describing a scratch (e.g., "the cue ball's gone down the sewer").

Also swan rest. A type of rest, similar to a spider in that the head is raised by longer supporting legs, but instead of a selection of grooves on the top for the cue to rest in there is only one, on the end of an overhanging neck, so that a player can get to the cue ball more easily if the path is blocked by two or more obstructing balls. Also known as the goose neck.

A game of pool played on a table shaped like a rectangle, with or without pockets.

This is a style of play where the player is required to stay on top of all the scoring practices. Scratches and points will disappear if they are not remembered.

To move a ball (usually deliberately) from a safe position, e.g. close to the middle of a cushion or in a cluster, so that it becomes pottable.

Nearly table-length distance between the cue ball and target object ball, or near cue and object balls and target pocket, i.e. a potentially difficult shot ("you sure left me a lot of green on that one").
The cloth covering the table.

This is the ball that sits in the front, or apex, position in the rack.

A barrel is how much money per game a player is betting. As in, "I have ten barrels at $20 a game".

English Amateur Billiards Association. The EABA is the governing body of amateur billiards in England, and as such is responsible for organizing various tournaments and events.

Any one of numerous acts which unethical players employ to rattle or upset their opponent. Taking, making noise, and chalking your cue while your opponent is shooting are all considered sharking tactics.

The white ball struck by the cue (and so used to strike other colored, numbered, object balls) during play.

Chiefly American: The cushion on the foot rail. Compare top cushion; contrast head cushion.

A directional pile created by the short fuzzy ends of fibers on the surface of cloth projecting upward from the lie and which create a favorable and unfavorable direction for rolling balls. The convention in most billiards games in which directional nap cloth is used is to brush the cloth along the table in the same direction of the nap, usually from the end that a player breaks. In snooker and UK eight-ball especially, this creates the effect of creep in the direction of the nap, the most-affected shot being a slow roll into a center pocket against the nap. It is commonly referred to in the fuller term "nap of the cloth." When nap is used in relation to woven cloths that have no directional pile, such as those typically used in the U.S. for pool tables, the term simply refers to the fuzziness of the cloth.

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.

When a ball is given as a handicap it often must be called (generally tacit). A wild handicap means the ball can be made in any manner specifically without being called.

The material which covers the bed and cushions of a pool table. The cloth used to cover a pool table is very special and can come in a variety of grades. Along with the general quality of the table itself, the cloth play a very important role in how a particular table plays.

The point in match play where both players (or teams) need only one more game (frame) victory to win the match or race.

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.

This is a shot where the cue ball caroms off a number of balls in a pin ball, back and forth, fashion to achieve a shot.

This game is played on a smaller octagonal table filled with bumpers in the middle and two more bumpers surrounding a hole on each side of the table. The game is played by trying to sink the balls into the opposite pocket by hitting the object ball directly instead of using a cue ball.