Definition of Rotation

Chiefly British: Same as duck, and stemming from the same obvious etymology.

A player who was not shooting well during a match but suddenly turns it around and starts playing better and more accurately. Also known as "Finding a stroke" or "Found their stroke".

This is a slang term created by Freddy Bentivegna to refer to a cluster of balls on your side of the table that do not lend to easy pocketing in a game of one pocket.

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.

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

This is English that turns into running action after contact with the object ball. This will open up the angle on a bank.

This describes when a player is trapped behind a ball. (n.) - This is also the amount of money a player is down after betting.

A short, jabbed draw stroke usually employed so as to not commit a foul (i.e. due to following through to a double hit) when the cue ball is very near to the target object ball.

A denigrating slang term for the mechanical bridge.

A particular shot where the object ball hits or grazes another object ball on the way to its pocket or toward hitting yet another object ball.

A (principally American) term in eight-ball for either of the set of seven balls (stripes or solids) that must be cleared before sinking the 8 ball. Borrowed from card games. Generally used in the generic, especially in rulesets or articles, rather than colloquially by players. See also group for the British equivalent.

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

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

In eight-ball, when all object balls are balls-on for either player.
A description of a break shot in which the rack (pack) is spread apart well. See also the open break requirement in some games' rules, including eight-ball and nine-ball.
In carom billiards, descriptive of play in which the balls are not gathered.

Same as gapper

Used when describing perfect play. "as if the balls had strings on them"

This is when a mistake is made in the shot and the resulting contact between balls forces you to miss the shot.

The pocket chosen to house the selected ball in your called shot.

Also bigs, big balls, big ones. In eight-ball, to be shooting the striped suit (group) of balls (9 through 15); "you're big, remember", "you're big balls" or "I've got the big ones". Compare stripes, yellows, high, overs; contrast little.

This is a low bet in a game with action.

A short and loose stroke performed in a manner similar to the way one throws a dart; usually employed for a jump shot. See also nip draw.

A predetermined number of games, usually played for a specified sum of money. Contrast race (a predetermined number of wins). Informally, sets may refer to gambling more generally, as in "I've been playing sets all day", even when the format is actually races or single games.

"Pocket billiards," or a game in which balls are shot into pockets.

A slang term for a cue, usually used with "piece", as in "that's a nice piece of wood".