Definition of Bad hit

The angle at which a ball approaches a rail, as measured from the perpendicular to the rail.

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.

A term used in snooker for the potting of all the balls that are racked at the beginning of the frame in a single break (run). The minimum total clearance affords 72 points (barring multiple reds being potted on a single stroke), in the pattern of red then yellow repeatedly until all reds are potted, then all of the colour balls. The maximum break is 147 (barring a foul by the opponent immediately before the break began).

One of the two pockets one either side of a pool table halfway up the long rails. They are cut shallower than corner pockets because they have a 180 degree aperture, instead of 90 degrees. In the UK the term centre pocket or middle pocket are preferred.

To sink a ball into a pocket.

See two-shot carry.

Describing a difficult pot: "the awkward cueing makes this shot missable."

A British term for a pot that requires very fine contact between cue ball and object ball. See also feather.

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 and CPA Leagues, 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.

American Poolplayers Association. This is the largest association of pool players in the world, and includes The Canadian Poolplayers Association. With numerous tournaments, including the U.S. Amateur championship, they are a force on the competition scene.
The APA has established the use of the "Equalizer" which offers handicaps to players and equalizes the playing field like in golf.

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.

Slang term for the cue ball.

Same as feather (US) or snick (UK)

Having the cue ball stop precisely where intended.
Having the cue ball stop at or near the center of the table on a forceful break shot (the breaking ideal in many games such as nine-ball);

This is playing to a higher winning score than eight in the game of one pocket.

This is the red colored object ball in carom games.
In snooker, any of the 15 balls worth 1 point each that can be potted in any order. During the course of a break a player must first pot a red followed by a colour, and then a red and colour, etc., until the reds run out and then the re-spotted six colours must be cleared in their order. Potting more than one red in a single shot is not a foul - the player simply gets a point for each red potted.
In blackball, one of two groups of seven object balls that must be potted before the black. Reds are spotted before yellows, if balls from both group must be spotted at the same time. Compare stripes; contrast yellow ball.
In carom billiards, the object ball that is neither player's cue ball.

A cue made specificaly for an individual player. The term may also describe a quality product of a low volume yielding cue maker who puts more time and effort into both the design and structural integrity of the cue stick, as opposed to a cue manufacturer that builds their cues in a more assembly line fashion.

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.

This is the portion of the butt of your cue just below the handle or wrap. This portion of the cue is made separately and often times cored out to ensure the proper weight balance within the full length of the cue. This portion of the cue is usually made with exotic wood that matches the wood in the forearm or in the points on the forearm. This section is used to highlight the design of the forearm, sometimes a re-creation, a reverse, or a rendition of the same pattern on a smaller scale.

The cue ball's position after a shot. "Good" or "bad" in reference to a leave describe respectively and advantageous or disadvantageous position for the next shot, or to leave an incoming opponent safe.

Also in the zone. Describes an extended period of functioning in dead stroke ("She's in the zone").

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 shot in which if the target is missed, the opponent is safe or will not have a desirable shot;
A shot in which there are two ways to score;
A shot in which a second ball is targeted to be pocketed, broken out of a cluster, repositioned or some other secondary goal is also intended.