Definition of Triangle

The way in which a player holds the butt end of the cue stick.
The wrap of the cuestick where the hand is placed, also known as the "grip area."

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

The useless but common practice of contorting one's body while a shot is in play, usually in the direction one wishes a ball or balls to travel, as if in the vain hope that this will influence the balls' trajectories; the term is considered humorous.

Means either push out or push shot, depending on the context.

Same as gutter table. A table with a ball return system, as opposed to a drop pocket table.

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.

Inadvertent english placed on the cueball by a failure to hit it dead center on its horizontal axis. It is both a common source of missed shots and commonly overlooked when attempts are made to determine the reason for a miss. In UK parlance this is usually called 'unwanted side'.

The use of the correct amount of cue ball speed in position play to achieve proper shape for a subsequent shot.

A situation in which a ball strikes another ball which is close to a rail and the struck ball rebounds back into the ball it was hit by; usually but not always unintended.

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.

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

Sometimes called spots and stripes, stripes and solids or, more rarely, bigs and littles or highs and lows.
All fifteen numbered balls are used in a conventional triangle rack.
Each player is assigned either the solid balls (1-7) or the striped balls (9-15). The object is to pocket all of your assigned balls and then pocket the 8-ball.

Also semi-massé shot. A moderate curve imparted to the path of the cue ball by an elevated hit with use of english (side); or a shot using this technique. Also known as a curve (US) or swerve (UK) shot. Compare massé.

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

This is an imaginary line that separates the halves of the table by crossing at the middle of the side of pockets.

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.

A denigrating slang term for the mechanical bridge.

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

To bungle a shot in a manner that leaves the table in such a fortuitous position for the opponent that there is a strong likelihood of losing the game or match. Contrast sell out.

To elevate the back of the cue on a shot.

Also known as a "power draw", means applying very powerful draw on the cue ball thereby causing the maximum amount of draw.

Local Bylaws are additional rules, policies, and procedures unique to an area in addition (or subtraction) to established Pool/Billiards/Snooker league rules. They are designed to cover local situations.

The Higher Education Snooker and Pool Council is a voluntary, not-for-profit organisation established to promote cue sports in institutions of higher education on the island of Ireland.

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