Definition of Open

This is English that turns into reverse English after contact with the object ball. This will close up the angle on a bank.

Chiefly British: Same as shark (senses 1, 2). The term appears in lyrics from The Mikado (1884) in relation to billiards, and developed from sharper (in use by at least 1681, but now obsolete) meaning "hustler" but not specific to billiards.

The ACS Canadian affiliate organization, the Canadian Cue Sport Association.

American CueSports Alliance. Their mission statement is "To heighten the interest and awareness of cue sports through the support and sanctioning of organized competition throughout the United States and North America."

The normal phenomenon where the object ball is pushed in a direction very slightly off the pure contact angle between the two balls. Caused by the friction imparted by the first ball sliding past or rotating against the other ball.

Same as angle of reflection.

Same as side rail.

In pool, the degree to which racked balls move apart upon impact by the cue ball as a result of a break shot.
In snooker, a shot sending the cue ball into the pack of red balls and separating them (after potting the ball-on). At least one split is usually necessary in each frame, since the original triangle of reds does not allow any balls to be potted reliably.

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.

These are fouls made in one turn and then on the next by the same player each time. Some games have a rule that a player will lose the rack or match with three succesive fouls.

A multi-game division of a match, as used in some league and tournament formats. For example, in a match between 2 teams of 5 players each, a 25-game match might be divided into 5 rounds of 5 games each, in which the roster of one team moves one line down at the beginning of each round, such that by the end of the match every player on team A has played every player on team B in round robin fashion.
A level of competition elimination in a tournament, such as the quarterfinal round, semifinal round and final round.

All-Africa Pool Association. The AAPA is a member of the WPA.

Side spin on the cue ball that causes it to unnaturally roll off a cushion (contacted at an angle) against rather than with the ball's momentum and direction of travel. If angling into a cushion that is on the right, then reverse english would be right english, and vice versa. The angle of deflection will be steeper (narrower) than if no english were applied. The opposite of running english, which has effects other than simply the opposites of those of reverse english.

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.

A rare and very difficult trick jump shot that turns into a draw shot upon landing. Requires precise application of spin in addition to the precise application of ball pressure to effectuate the jump. Jump draws are fairly often seen in professional trick shot competition.

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

A misnomer for hand talc.

Also piquet. Either a massé shot with no english, or a shot in which the cue stick is steeply angled, but not held quite as vertical as it is in full massé.

To play even; without a handicap. Also called heads up.

An intentionally amateurish stroke to disguise one's ability to play.

A set of paired balls in the game of cribbage pool that have a number value which combined equal 15. For example, the 8 ball and the 7 ball added together equal 15 and thus constitute one cribbage if pocketed in succession.

This is a long distance shot that is given to your opponent as a challenge to make because it often works well as a safety (defense) when a better one is not available.

Also nurse shot, nursery shot. In carom games such as straight rail, balkline and cushion caroms, where all the balls are kept near each other and a cushion, and with very soft shots, can be "nursed" down a rail on multiple successful shots that effectively replicate the same ball setup so that the nurse shot can be repeated again (and again, etc.). Excessive use of nurse shots by players skilled enough to set them up and pull them off repeatedly at will is what led to the development of the balkline carom billiards game variations, and repetitive shot limitation rules in English billiards. A clear example of why: In 1907, Tom Reece scored a record break of 499,135 consecutive points over a period of five weeks, without a miss, using the cradle cannon nurse shot.

This term refers to a cue stick that is bent or warped, so that the straightness, or lack thereof, of the cue offers less than ideal play. This can occur from storing the cue in the wrong atmosphere, i.e. too warm or humid, or from the quality of wood used during construction. Some cues are coated with fiberglass, carbon fiber or graphite in order to avoid warping.