Definition of 4 pins

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.

24 Random Essential Billiards Terms

An imaginary line running horizontally across a billiards table from the second diamond (from the foot end of the table) on one long rail to the corresponding second diamond on the other long rail. The foot string intersects the long string at the foot spot. It is rarely drawn on the table.
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.
The break box is a zone in the "kitchen" of the head (British: bottom) of the table, from which the break shot must be taken with the cue ball,
This is the act of looking over the stack, pile of balls in the middle of the table, to see if there are any opportunities in the game of one pocket.
A slang term for a cue, usually used with "piece", as in "that's a nice piece of wood".
Same as cue.
A highly abrasive tip tool used to shape an unreasonably flat new cue tip, or misshapen old one, into a more usable, consistently curved profile, most commonly the curvature of a nickel or dime (or equivalently sized non-US/Canadian coin) for larger and smaller pool tips, respectively. Similar to a scuffer, but deeper and rougher.
This is a carom shot that utilizes english and only two rails to achieve three cushion contacts.
Same as cloth (deprecated; it is factually incorrect).
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.

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".

This playing to a number less than eight in a game of one pocket.
A type of rest, with a straight shaft and "x"-shaped head for resting the cue upon.
A pool ball that was meant to go into the pocket, but got caught up by the jaw and ended up bouncing back and forth before stopping short of the pocket.
This is the way your hand is configured to support the shaft of the cue during a shot.
A term applied especially in snooker for a type of double off three cushions, e.g. around the baulk colours and into a centre pocket. Such a shot is very difficult to make and would not normally be played as anything more than a shot for nothing.
The imaginary line drawn perpendicular to the impact line between the cue ball and an object ball. The cue ball will travel along this line after impact with an object ball if it has no vertical spin on it (is sliding) at the moment of impact on a non-center-to-center collision. See also stun shot.
Also solid, solid ones, solid balls. The non-striped ball suit (group) of a fifteen ball set that are numbered 1 through 7 and have a solid color scheme (i.e., not including the 8 ball). As in, "I'm solid", or "you've got the solids". Compare low, small, little, reds, spots, dots, unders; contrast stripes.

1- Short for "pool shark", poolshark (US); sharp, "pool sharp" (British)

2- Verb: To perform some act or make some utterance with the intent to distract, irritate or intimidate the opponent so that they do not perform well, miss a shot, etc. Most league and tournament rules forbid blatant sharking, as a form of unsportsmanlike conduct, but it is very common in bar pool.
Noun: Another term for hustler.
Noun: A very good player. This usage is common among non-players who often intend it as a compliment and are not aware of its derogatory senses .

Displacement of the cue ball's path away from the parallel line formed by the cue stick's direction of travel; occurs every time english is employed. The degree of deflection increases as the amount of english applied increases. It is also called squirt, typically in the United States.
Also winner. A shot in which the cue ball is used to pot another ball. In snooker and most pool games doing this is known as potting, pocketing or sinking the targeted ball. The term derives from this hazard winning the player points, while losing hazards cost the player points, in early forms of billiards. Whether the ball is an object ball or an opponent's cue ball depends upon the type of game (some have two cue balls). The move will score points in most (but not all) games in which hazards (as such) apply, such as English billiards (in which a "red winner" is the potting of the red ball and a "white winner" the potting of the opponent's cue ball, each worth a different amount of points).
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.
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.
This is the imaginary line that a ball would need to follow in order for it to result in an effective bank shot.