Definition of Head

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.

A line, sometimes imaginary (especially in American pool), sometimes drawn on the cloth, that runs horizontally across the table from the second diamond (from the head rail) on one long rail to the corresponding second diamond on the other long rail. In most pool games, the opening break shot must be performed with the center (base) of the cue ball behind the head string (i.e. between the head string and head rail). The head string intersects the long string at the head spot, and delimits the kitchen (and, in European nine-ball, the outer boundary of the break box). The head string's position is always determined by the diamonds, in contrast to the similar but different baulk line, the position of which is determined by measurement from the bottom cushion (head cushion).

When an opponent either purposely successfully executes a defensive shot or misses their shot resulting in a bad leave for the next player.
Example: "I was left bad every time he missed his shot".

Same as cue.

As a result of the opening break shot (the "snap"), usually said of winning by pocketing the money ball ("won on the snap", "got it on the snap", etc.) Employed most commonly in the game of nine-ball where pocketing the 9 ball at any time in the game on a legal stroke, including the break shot, garners a win.

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.

Pronounced "No-Rango". A norengo refers to what should be an easy straight in shot where the object ball is usually very close to the pocket. But the shooter strikes the ball harder than they should and the result is the object ball rattling out of the pocket and a missed shot.
Also see Lorengo.

Confederation Panamerica of Billiards

Describes the propensity of pockets to more easily accept an imperfectly aimed ball shot at a relatively soft speed, that might not fall if shot with more velocity ("that ball normally wouldn't fall but he hit it at pocket speed"). The less sensitive to shot-speed that a pocket is, the "faster" it is said to be.
Describes the velocity of an object ball shot with just enough speed to reach the intended pocket and drop. "Shoot this with pocket speed only, so you don't send the cue ball too far up-table."

When the object ball banked of a rail goes directly in a pocket without kissing or touching any other object balls.

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.

A material, usually leather, placed on the end of a cue stick that comes in contact with the cue ball.

To disguise the level of one's ability to play in various ways such as using a lemonade stroke; intentionally missing shots; making an uneven game appear "close"; purposefully losing early, inconsequential games. Sandbagging is a form of hustling, and in handicapped leagues, considered a form of cheating. See also dump and on the lemonade.

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.

A deliberate foul that leaves the balls in a safe position, reducing the risk of giving a frame-winning chance to the opponent. The miss rule in snooker was implemented primarily to discourage the professional fouls.

1- Pocketing of the cue ball in pocket billiards. In most games, a scratch is a type of foul. "Scratch" is sometimes used to refer to all types of fouls.

2- British term/slang for Draw

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.

Any shot where the cue ball is intentionally jumped into the air to clear an obstacle

The International Pool Tour is a professional sports tour created in 2005 by Kevin Trudeau and hosted by Rebecca Grant. It aims to elevate pool (pocket billiards) to the level of other modern sports.

In the carom games, any shot where the end result is all the balls near each other; ideally, in position for the start of a nurse on the next stroke.

The placement of player(s) automatically in a tournament where some have to qualify, or automatic placement in later rounds.

A bank shot is when the shooter (player) bounces the cue ball or the object ball (after it is hit by the cue ball) off a rail in an attempt to make the shot. A successful bank shot will result in sinking the object ball or a defense that will make it very difficult for the opponent to attempt their shot.

A form of doubles play in which the two team members take turns, playing alternating shots during an inning (i.e. each team's inning consists of two players' alternating visits, each of one shot only, until that team's inning ends, and the next team begins their alternating-shot turn.) Effective scotch doubles play requires close communication between team partners, especially as to desired cue ball position for the incoming player. Like "english", "scotch" is usually not capitalized in this context. The term is also used in bowling, and may have originated there.

In snooker and other British usages, a break of 50-99 points (100 points or more being called a century), which involves potting at least 12 consecutive balls (i.e. the last 3 reds with at least 2 blacks and a pink, followed by all the colours).