Definition of clock

Verb: "To Clock" To carefully note the abilities or betting inclinations of other players for future reference.

24 Random Essential Billiards Terms

One of two sharp, jutting curves of the cushions either side of a pocket at the points where cushion and pocket meet, forming the jaws of the pockets. Also known as a point, a tittie or a horn.
(Computerized Numerical Control) This is a special appliance used by many cue manufacturers to design the inlays on a cue to precision accuracy. Often times it is looked down upon because this technology departs from the previous standard of "handcrafting" inlays, using a pantograph tool. However, the new technology allows for much more precise cuts at a quicker pace. If you are looking to save some money and appreciate the man made designs that are computer inlayed in your cue, then CNC is the technology for you.
Also lows, low, low ones. In eight-ball, to be shooting the solid suit (group) of balls (1 through 7); "you're low, remember", "you're low balls" or "I've got the lows." Compare solids, reds, little, spots, dots, unders; contrast high.
To enter the loser bracket in a double elimination tournament, or otherwise slip in standing in other tournament formats (i.e., to lose a game/frame/round/match, but still remain in the competition).
This is a ball that is left in a position that allows an easy shot, while time is spent working with other balls to better your position in the game.
Balls remain unmoved after a player's shot.
Anything that causes a foul according to the rules of a game.
Describes a player who needs only one more game win to be victorious in the match.
The ball meant to be struck and sunk in your called shot.

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.

Also known as Free-stroking. This is slang for when a player begins to play untroubled and relaxed because they have built up a substantial lead.
An abrasive tip tool used as a grinder to roughen the cue tip to better hold chalk after it has become hardened and smooth from repeated impacts with the cue ball. Tappers serve the same purpose, but are used differently. Similar to a shaper, but shallower and less rough.
The person who is a provider of all or part of a player's stake (money) for a gambling session in which one is not a player.
Also known as a "Dirty Defense" or "Dirty Foul". To intentionally miss a shot (that results in a foul) in order to create a position for the cue ball that makes it hard for the other player to execute their shot. Not to be confused with a "Safety", since a safety is a legal hit.
A cluster of balls. In snooker, the bunch of reds that are typically left below the pink spot in the early stages of a frame, not including those reds that have been released into pottable positions.
During a set if the opponent does not win a single game, they are said to have been skunked.
The way in which a player holds the butt end of the cue stick.
The wrap of the cuestick where the hand is placed, also known as the "grip area."
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.
A defensive action taken when a player either has no "makeable" or "high percentage" shot or chooses to leave his opponent in a difficult situation. It is a legal shot and is not considered to be dirty pool. A safety must still conform with the rule concerning hitting the correct ball first and striking a rail afterwards. If a correct ball is accidentally pocketed while playing safe, the shooter must continue to shoot.
The first shot in a game - aimed at a set of racked balls.
To execute the first shot in a new game.
In snooker this term can be use to indicate a series of successive shots completed by a single player.
A shot in which the cue ball is potted after caroming off another ball. In snooker and most pool games doing this would be a fault (foul), but the move will score points in many games in which hazards (as such) apply, such as English billiards, or in the final or game point in Cowboy pool. The term derives from this hazard costing the player points in early forms of billiards.
Side spin on a cue ball on the opposite side of the direction of the cut angle to be played (right-hand english when cutting an object ball to the left, and vice versa). In addition to affecting cue ball position, outside english can be used to decrease throw.
This term refers to a low percentage one pocket shot.
USA Pool League. A pool league structured exclusively around eight-ball match play.