Definition of Open

A well calculated successful slop shot that is usually hit a little harder than it should be and results in a pocketed ball or two without any fouls.

This is a bank shot that goes off of the head rail and then straight to the pocket at the other end of the table.

Similar to run out, but more specific to making all required shots from the start of a rack. Also known as also break and run or break and dish.

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.

A point bead on a scoring string.

The intersection of the head string and long string, which is usually not marked on a table with a spot decal, unlike the foot spot, though some pool halls mark both spots so that racking can be done at either end of the table, and wear on the cloth from racking and breaking is more evenly distributed.

The use of the correct amount of cue ball speed in position play to achieve proper shape for a subsequent shot.

In three cushion billiards, the most standard shot where the third ball is advantageously placed in a corner.

A type of spin imparted to the cue ball to make it rebound from a cushion at a shallower angle than it would if the spin had not been used.

A ball that is easily made from many positions on the table but which is left untouched while the rack is played, so that in the event the player gets out of position, the shooter has an insurance shot. Typically an insurance ball will be in or near the jaws of a pocket.

One-pocket (often spelled one pocket) is a two-player (or -team) pocket billiards (pool) game. The object of the game is to score points by pocketing (potting) pool balls into specific pockets. A point is made when a player makes any object ball into that player's designated pocket. The winner is the first to score an agreed-upon number of points (most commonly 8). The player making the break shot (typically after winning the lag) chooses a foot corner pocket for the rest of the game; all of that shooter's balls must be shot into that pocket. All of the opponent's balls must be made in the other foot corner pocket.

Literally, a pocket, but generally used in the phrases losing hazard - potting (pocketing the cue ball off another ball - and winning hazard - using the cue ball to pot another ball - the two types of legal shots that pocket balls in games in which the term is used at all, which is very few today. The term principally survives in English billiards, in which both types of shots are point-scoring. Formerly, a large number of different games made use of the two types of hazards as point scorers or losers in various different ways (thus their suggestive names). The term ultimately derives from holes or pockets in the table to be avoided, in very early forms of billiards. While the terms are disused in pocket billiards today, their lingering effect is obvious, as the vast bulk of such games focus on making winning hazards and avoiding losing hazards (a notable exception being Russian pyramid in which both are legal shots).
In golf billiards, an area of the table (sometimes marked) that a player will be penalized for entering if their ball does not leave. Derives from the use of the term in the outdoor game of golf.

This a shot that hits the object ball at the nine ball to see if you can get lucky by sinking the nine ball in any pocket. (also see Cheese the Nine and Rolling the Cheese).

Same as angle of reflection.

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."

A short, jabbed draw stroke usually employed so as to not commit a foul (i.e. due to following through to a double hit) when the cue ball is very near to the target object ball.

A type of nurse used in carom billiards games. With one object ball frozen to a cushion and the second object ball just slightly away from the rail, the cue ball is gently rebounded across the face of both balls, freezing the away ball to the rail and moving the frozen ball away the same distance its partner was previously, resulting in an identical but reversed configuration, in position to be struck again by the cue ball from the opposite side.

A requirement under some pocket billiards rulesets that either an object ball be pocketed, or at least four object balls be driven to contact the cushions, on the opening break shot.

A foul where the rules are blatantly, intentionally violated, with a stiffer penalty (e.g., loss of game) than normal.

A players skill level, ball advantage or match advantage when using a handicapping system.

When the object balls in straight rail pool are lined up close to each other, but extending out from the cushion, and you choose to bounce off the first object ball at the cushion and then come back to graze the second object ball. This technique can be used to continue scoring points as long as you are efficient with the shot.

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.

In blackball, a penalty conceded by a player after a fault. The incoming opponent is then allowed to miss twice before the faulting player is allowed another visit. Many local rules state the in-hand from the "D" or baulk (or if the opponent potted the cue ball, from anywhere) nature of the second shot is lost if a ball is potted on the first shot, that it is lost if the ball potted in the first shot was that player's last coloured ball (object ball in their group), and/or that there is only ever one shot on the black after a fault.

This is to watch a match with such intensity that there is worry, usually because of a wager on the game.