Definition of black ball

In snooker, the highest-value colour ball on the table, being worth seven points. In some (especially American) snooker ball sets it is numbered "7" on its surface.
The black ball (usually numbered "8") in the eight-ball variant game blackball (and its variants); also the common British term for the slightly larger but otherwise identical 8 ball in a kelly pool set (a.k.a. American or WPA pool set).

24 Random Essential Billiards Terms

The table reserved for games played for money or the best table in the house. This table is always of better quality and regularly maintained. Money tables are most commonly reserved for big action.
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.
When you hit the object ball you are aiming for (or the manditory next ball) without the cue ball hitting other object balls first.
This describes a player who is not particular good at completing long shots. They may have other skills that help them in the game of one pocket pool, but when faced with long shots; their execution is less than perfect.
Short for right english (side), i.e. side spin imparted to the cue ball by stroking it to the right-hand side of its vertical axis. Contrast left.
Also pro side of the pocket and missing on the professional (or pro) side of the pocket. Sometimes "of the pocket" is left off the phrase. To err on the side of overcutting a difficult corner pocket cut shot rather than undercutting in nine ball; "missing on the professional side of the pocket." So called because experienced players understand that on a thin cut, overcutting the object ball to a corner pocket will far more often leave the object ball in an unfavorable position for the incoming opponent than will an undercut, which often leaves the object ball sitting in front of or nearby the pocket it had been intended for on a miss. By contrast, in eight-ball, except when both players are shooting at the 8 ball, the incoming player after a miss is shooting for different object balls, so this maxim does not apply, and the opposite may be good strategy as, if the object ball stays near the pocket through an undercut, it is advantageously positioned for a subsequent turn and may block the opponent's use of the pocket.
A player's (or doubles team's) turn at the table, usually ending with a failure to score a point or to pocket a ball, depending on the game, a foul, a safety or with a win. In some games, such as five-pins and killer, a player's inning is always limited to one shot, regardless of the intent and result of the shot. Usually synonymous with visit, except in scotch doubles format. The term is sometimes used to mean both players'/teams' visits combined, e.g. when referring to which inning in which a memorable shot occurred.
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.
This is your pocket for sinking balls in a one pocket game.
This is a blemish added to the table in order to help execute a shot; these marks are not allowed and result in a foul.
Also lady's aid or girly stick. A denigrating term for the mechanical bridge.
Chiefly American: The half of the table in which the object balls are racked (in games in which racked balls are used). This usage is conceptually opposite that in British English, where this end of the table is called the top. Contrast head.
Also straight eight-ball. Same as bar pool. Not to be confused with the games of straight pool or straight rail.
This is the point on the object ball where the cue exactly impacts or the point at which two balls touch when they impact.
Chiefly British: bank shot played up and down the longer length of the table off a short rail and into a corner pocket, as opposed to the more common bank across the short length into a center pocket or corner.
This is the white ball in carom games which is separated from the clear ball by a marking (usually a dot or spot).
Ten Ball is a rotation is a rotation game very similar to nine-ball, using ten balls instead of nine, and with the 10 ball instead of the 9 as the "money ball".
The object of the game is pocket the 10-ball on any legal shot.
As in many other sports, "legal" means not causing or likely to cause a foul (the opposite being illegal). A legal hit is one in which the requirements for a non-foul hit are met (e.g., in nine-ball, the lowest-numbered ball on the table was hit by the cue ball first, and at least one object ball was pocketed, or any ball reached a cushion, after the hit on the first object ball.). A legal shot is one in which no foul of any kind was involved (e.g. there was not a double hit by the cue, the player's bridge hand did not move a ball, etc.). A legal stroke is one in which the cue stroke obeyed the rules (e.g. the shooter did not perform an illegal jump shot by scooping under the cue ball with the cue tip). A legal ball is a ball-on, an object ball at which it is permissible for the player to shoot. And so on. The term can be used in many ways consistent with these examples ("legal pocket" in one-pocket, "legal equipment" under tournament specifications, etc.).
To fail to make a legal shot.
Name for the ball that when pocketed, wins the game, or any ball that when made results in a payday such as a way in the game of Chicago.
This is a shot where the cue ball contacts an object ball and moves it along a path, but because the cue ball is still in motion it re-contacts the object ball and pushes it in the pocket after it stops.
This is a particular ball which lends itself to be used as a "blocker" or a "protector."
To use a particular ball as security by playing a safety or leaving it where it will act as one.
When the cue ball contacts three or more cushions in carom games.
This is the state after which the person returning the break has had the opportunity to catch and even the field after the breakers advantage.