Glossary, A to Z.

Short definitions of the terms used across this site. Each links to the page that covers it in depth.

30-degree rule: A rolling cue ball hitting an object ball between a quarter-ball and three-quarter-ball hit deflects close to 30 degrees from its original path. (Cue ball control)
90-degree rule: With a stun hit, the cue ball and object ball separate at 90 degrees. (Cue ball control)
Back-hand english (BHE): Applying side spin by pivoting the cue with the grip hand while the bridge stays put, which can cancel squirt. (English)
Balkline: A carom game with lines on the cloth that limit how many points can be scored in one area. (Snooker and carom history)
Ball in hand: After certain fouls, the incoming player may place the cue ball anywhere (or, in some situations, anywhere in the kitchen). (Rules overview)
Bank shot: A shot that sends the object ball off one or more cushions into a pocket. (Banks and kicks)
Bar box: A "7-foot" table; exact sizes vary by maker. (Parts of the table)
Bridge: The hand (or mechanical device) that supports and guides the front of the cue. (Bridges)
Cheating the pocket: Aiming the object ball away from the pocket's center to change the cue ball's angle without side spin. (English)
Cut-induced throw (CIT): The object ball being dragged slightly off line by friction on a cut shot; largest on slow stun shots near a half-ball hit. (Aiming)
Diamonds (sights): Markers on the rails at eighths of the table's length and quarters of its width, used for aiming systems. (Parts of the table)
Drag shot: A shot with backspin that slows the cue ball on its way to the object ball. (Cue ball control)
Draw: Backspin that makes the cue ball come back after contact. (Cue ball control)
English: Side spin, put on by striking the cue ball left or right of center. (English)
Equalizer: The APA's handicap system, using skill levels to set how many games or points each player needs. (Leagues)
Fargo Rating: A player rating on FargoRate's worldwide scale; a 100-point gap means about two wins for every one. (FargoRate)
Follow: Topspin that makes the cue ball continue forward after contact. (Cue ball control)
Foot spot: Where the foot string crosses the long string; the front ball of the rack sits here. (Parts of the table)
Front-hand english (FHE): Applying side spin by pivoting the cue at the bridge hand. (English)
Ghost ball: The imaginary position the cue ball must occupy at contact to send the object ball to its target. (Aiming)
Head string: The line marking off the quarter of the table nearest the head rail. (Parts of the table)
Inning: A player's turn at the table.
Jump shot: Striking the cue ball downward so it bounces off the slate and over an obstacle; a scoop under the ball is treated as a miscue, and rules penalize an intentional one. (Jump and massé)
Kick shot: A shot that sends the cue ball off one or more cushions before it reaches an object ball. (Banks and kicks)
Kitchen: The area between the head string and the head rail, where most breaks start. (Parts of the table)
Lag: Each player shoots a ball to the foot cushion and back; the one closest to the head cushion chooses who breaks. (Tournament formats)
Long string: The line down the center of the table lengthwise. (Parts of the table)
Massé: A shot with an elevated cue and side spin that curves the cue ball around an obstacle. (Jump and massé)
Measles ball: A cue ball with dots so spin is visible. (Pool balls)
Miscue: When the tip slips off the cue ball; the miscue limit is about half the ball's radius from center. (Cue ball control)
Natural roll: A cue ball rolling without sliding; it starts when the tip hits about 2/5 of the radius above center. (Cue ball control)
Phenolic: A hard resin used for premium balls and for break and jump cue tips. (Pool balls)
Pre-shot routine: The same sequence of steps before every shot: visualize, chalk, aim standing, get down, stroke. (The stroke)
Race to X: A match format: the first player to win X racks wins. (Tournament formats)
Safety: A defensive shot that leaves the opponent in a difficult position. (Safety play)
Scratch: Pocketing the cue ball, a foul. (Rules overview)
Squirt: The cue ball pushing off the cue's line when struck off center; driven by the mass at the end of the shaft. (English)
Squerve: The combined effect of squirt and swerve. (English)
Stop shot: A straight-in stun shot where the cue ball stops dead at contact. (Cue ball control)
Stun: A hit where the cue ball has no top or bottom spin at contact. (Cue ball control)
Swerve: The curve of a sliding cue ball that has side spin, made worse by an elevated cue. (English)
Tangent line: The line at right angles to the object ball's path; a stunned cue ball travels along it. (Aiming)
Template rack: A thin sheet with cut-outs that holds the balls tight for the break and is removed afterward. (Accessories)
Throw: The object ball leaving slightly off the line of centers because of friction at contact. (English)
Trisect rule: On a draw shot with "good action" under about 40 degrees, the cue ball ends up about three times the cut angle from its original line. (Cue ball control)
Two-way shot: A shot that leaves you in good shape whether you make it or miss. (Safety play)
Vision center: The head position relative to the cue from which a straight shot looks straight. (Stance and grip)

Sources