Definition of extension

Any mechanical aid that serves to extend the length of the player's cue, normally added to the end of the butt either by clipping around the end or screwing into the base. Though extensions are used for pool, it is more common in snooker because of the significantly larger table size.
In a tournament where players get limited time to make their shots (common in televised matches), an extension is extra time granted before making a shot; players have a limited number of extensions in each frame.

24 Random Essential Billiards Terms

One of the two pockets one either side of a pool table halfway up the long rails. They are cut shallower than corner pockets because they have a 180 degree aperture, instead of 90 degrees. In the UK the term centre pocket or middle pocket are preferred.
A British term (especially in snooker) for the splitting of a group of balls when another ball is sent into them, typically with the intent of deliberately moving them with the cue ball to develop them.

1- A tip tool with fine, sharp points used to roughen the cue tip to better hold chalk after it has become hardened and smooth from repeated impacts with the cue ball. Tappers are firmly tapped on or pressed against the tip. Scuffers serve the same purpose, but are used differently.

2- Describes a shot where one has a chance to miscue. Usually heard in reference to long draw shots. As in, "It's a tip-tapper!".

A misnomer for hand talc.
This describes a shot in snooker where the cue contacts more than one object ball.
When a successful non penalized break is achieved which gives the object balls a broad spread on the table.
Chiefly Australian: Same as a force follow shot.
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."
Any ball that may be legally struck by the cue ball.
A barrel is how much money per game a player is betting. As in, "I have ten barrels at $20 a game".
The desired angle that must be created between the path of the cue ball and the path of the object ball upon contact to pot the object ball. It is usually measured to the center of the pocket. See also aiming line.
The precise center of the pool table.
This is a ball that is left in a position that allows an easy shot, while time is spent working with other balls to better your position in the game.
Also solid, solid ones, solid balls. The non-striped ball suit (group) of a fifteen ball set that are numbered 1 through 7 and have a solid color scheme (i.e., not including the 8 ball). As in, "I'm solid", or "you've got the solids". Compare low, small, little, reds, spots, dots, unders; contrast stripes.
A pool table spread in which the balls are extremely easily positioned for a run out, and where little movement of the cue ball on each shot is necessary to obtain position on the next.
A slang term for a cue, usually used with "piece", as in "that's a nice piece of wood".
An instance of contact between balls, usually used in the context of describing an object ball contacting another object ball (e.g. "the two ball kissed off the twelve ball"), or in snooker the cue ball making contact with a ball after the initial contact with the object ball. If the player's intention was to cause two object balls to kiss (e.g. to pocket a shot ball after a ricochet off a stationary one), it is often called a kiss shot.
A rare and extremely difficult trick jump shot that turns into a massé upon landing. Requires very precise application of spin in addition to the precise application of ball pressure to effectuate the jump. Turn-of-the-20th-century World Balkline Champion Jacob Schaefer Sr. was known to daringly perform jump massés in competition.
Also known as back spin, a type of spin applied to the cue ball by hitting it below its equator, causing it to spin backwards even as it slides forward on the cloth. Back spin slows the cue ball down, reduces its travel, and narrows both the carom angle after contact with an object ball, and angle of reflection off a cushion. There are several variant terms for this, including "bottom" and "bottom spin" in the US and "screw" in the UK. Draw is thought to be the first spin technique understood by billiards players prior to the introduction of leather tips, and was in use by the 1790s.
Describing a pot played at such a pace as to just reach the pocket and drop in without hitting the back.
An upright pin, which looks like a miniature bowling pin, cone or obelisk. Skittles, as employed in billiards games, have been so-called since at least 1634. One standardized size, for the largely Italian and South American game five-pins, is 25 mm (1 in.) tall, with 7 mm (0.28 in.) round bases, though larger variants have long existed for other games such as Danish pin billiards. Depending upon the game there may be one skittle, or several, and they may be targets to hit (often via a carom) or obstacles to avoid, usually the former. They are also sometimes called pins, though that term can be ambiguous. Because of the increasing international popularity of the Italian game five-pins), they are sometimes also known even in English by their Italian name, birilli (singular birillo). Skittles are also used as obstacles in some artistic billiards shots. #Flat, thin rectangular skittles, somewhat like large dominoes, approximately 6 in. tall by 3 in. wide, and placed upright like an obelisks on the table in specific spots, are used in the obsolescent and principally Australian games devil's pool and victory billiards. Depending upon the exact game being played, there may be one pin, or several of various colors (e.g. ten white and two black in devil's pool), and they may be targets or obstacles, most commonly the latter. They are usually made of plastic, and are increasingly difficult to obtain, even from Australian billiards suppliers. A black obelisk skittle of this sort features prominently, as a particularly dire hazard, in several scenes of sci-fi/pool film Hard Knuckle (1992, Australia). Skittles as used in billiards games date to ground billiards (13th century or earlier) played with a mace, and hand-thrown games of bowls from at least the same era using the same equipment. Ball games using a recognizable form of skittle are known from as early as ca. 3300 BCE in Ancient Egypt.
A semicircle with an 11½ inch (291 mm) radius, drawn behind a snooker table's baulk line, centred on the middle of the line, and resembling the upper case letter "D" in shape. The "D" is also used in English billiards and sometimes also in blackball and other pool games played on British-style tables.
English Amateur Billiards Association. The EABA is the governing body of amateur billiards in England, and as such is responsible for organizing various tournaments and events.
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.