Definition of two shots

In blackball, a penalty conceded by a player after a fault. The incoming opponent is then allowed to miss twice before the faulting player is allowed another visit. Many local rules state the in-hand from the "D" or baulk (or if the opponent potted the cue ball, from anywhere) nature of the second shot is lost if a ball is potted on the first shot, that it is lost if the ball potted in the first shot was that player's last coloured ball (object ball in their group), and/or that there is only ever one shot on the black after a fault.

24 Random Essential Billiards Terms

This is a ball that is positioned near your pocket that can be used to kiss off of when sinking another object ball.
A denigrating slang term for the mechanical bridge.
A pool table where two shims have been placed on the sides of each pocket (in the jaws beneath the cloth), making the pockets "tighter" (smaller). Such tables are "tougher" than unshimmed or single-shimmed tables.
Chiefly British: The cushion on the top rail. Compare foot cushion; contrast bottom cushion.
A geometric form, usually aluminum, wooden or plastic, used to assist in setting up balls in games like eight-ball, nine-ball, and snooker. The rack allows for more consistently tight grouping of balls, which is necessary for a successful break shot. In most games a triangle-shaped rack capable of holding fifteen balls can be employed, even if the game calls for racking less than a full ball set, such as in the game of nine-ball. For further information, see the Rack (billiards) main article.
In some games, refers to a single frame.
Describes lucky or unlucky "rolls" of the cue ball; "I had good rolls all night; "that was a bad roll." However, when said without an adjective ascribing good or bad characteristics to it, "roll" usually refers to a positive outcome such as in "he got a roll".
The roll: same as the lag.
Also littles, little ones, little balls. In eight-ball, to be shooting the solid suit (group) of balls (1 through 7); "you're little, remember", "you're the little balls" or "I've got the littles". Compare small, solids, reds, low, spots, dots, unders; contrast big.
An outgrowth of the training template concept, a racking template is a racking tool used in place of a traditional rigid ball rack for pool or snooker balls, consisting of a very thin, e.g. 0.14 mm (0.0055 in), sheet of material such as paper or plastic with holes into which object balls settle snugly against one another to form a tight rack (pack). The template is placed, stencil-like, in racking position, with the lead ball's hole directly over the center of the foot spot. The balls are then placed onto the template and arranged to settle into their holes, forming a tight rack. Unlike with a training template, the balls are not tapped to create divots, and instead the template is left in place until after the break shot at which time it can be removed (unless balls are still sitting on top of it). Manufacturers such as Magic Ball Rack insist that racking templates are designed "to affect the balls to a minimum", and while pro player Mike Immonen has endorsed that particular brand as a retail product, as of September 2010, no professional tours nor amateur leagues have adopted that or any other racking template. Although Magic Ball Rack implies development work since 2006, other evidence suggests invention, by Magic Ball Rack's founder, in mid 2009, with product announcement taking place in September of that year.
Exact opposite of fast, all senses.
Literally, a pocket, but generally used in the phrases losing hazard - potting (pocketing the cue ball off another ball - and winning hazard - using the cue ball to pot another ball - the two types of legal shots that pocket balls in games in which the term is used at all, which is very few today. The term principally survives in English billiards, in which both types of shots are point-scoring. Formerly, a large number of different games made use of the two types of hazards as point scorers or losers in various different ways (thus their suggestive names). The term ultimately derives from holes or pockets in the table to be avoided, in very early forms of billiards. While the terms are disused in pocket billiards today, their lingering effect is obvious, as the vast bulk of such games focus on making winning hazards and avoiding losing hazards (a notable exception being Russian pyramid in which both are legal shots).
In golf billiards, an area of the table (sometimes marked) that a player will be penalized for entering if their ball does not leave. Derives from the use of the term in the outdoor game of golf.
This is the highest number of consecutive points scored during an inning of continuous pool play.
This is English that turns into running action after contact with the object ball. This will open up the angle on a bank.
A line, sometimes imaginary (especially in American pool), sometimes drawn on the cloth, that runs horizontally across the table from the second diamond (from the head rail) on one long rail to the corresponding second diamond on the other long rail. In most pool games, the opening break shot must be performed with the center (base) of the cue ball behind the head string (i.e. between the head string and head rail). The head string intersects the long string at the head spot, and delimits the kitchen (and, in European nine-ball, the outer boundary of the break box). The head string's position is always determined by the diamonds, in contrast to the similar but different baulk line, the position of which is determined by measurement from the bottom cushion (head cushion).

1 - This is a shot in snooker where the cue ball follows a struck object into the pocket.

2- This is the male end of the joint located at the base of the shaft. This threaded piece, usually made of metal, connects the shaft with the forearm. The length, width, pitch and depth of threading of the pins vary from joint to joint, but most offer you a flat-faced wood-to-wood connection with the collar. This type of connection will deliver a softer hit. For a harder hit, some pins have a protruding tip without threads that directs the shaft concentrically with a pin that is buried in the collar at the joint. If you want to keep the pin of your shaft safe when your cue is dismantled, it is easy and important to use a joint protector that simply screws over your pin.

This is a particular shot where the potential for a miscue is higher because of the amount of draw that is attempted on the cue ball.
When the rules of the opening break are broken. Ex: If not enough balls contact with rails off the break.
This is when a player has scratched and the foul in one pocket calls for them to spot a ball, but not able to be spotted at the time. In this case a coin is usually placed on the side of the table to keep tabs.
Alternate name for the cue ball.
In carom billiards games, a term for the opponent's cue ball, which for the shooting player is another object ball along with the red.
Also split shot. In pool, a type of shot in which two object balls are initially contacted by the cue ball simultaneously or so close to simultaneously as for the difference to be indistinguishable to the eye. In most sets of rules it is a foul if the split is one in which one of the object balls is a (or the only) legal target (ball-on) and the other is not; however, such a split is commonly considered a legal shot in informal bar pool in many areas if it is called as a split and does appear to strike the balls simultaneously).
Feel generally refers to that elusive quality that makes one cue feel special or superior to another. In essence, it is the cumulative effect of all of a cues characteristics, including weight, shaft diameter, balance, grip material, length, etc. It can vary greatly from one player to another. A cue that feels great to one player does not necessarily fell good to another.
This is a play where the shot of the cue ball is meant to end up in a certain place to loose your turn, but makes the next attempt difficult for your opponent. The shot is turned over, but will often times lead to a foul, giving you the ball back with a different view or ball in hand. This "safety" play is important if your shot isn't ideal, and you are likely to turn the ball over anyway.
In snooker, the abandonment of a frame upon agreement between the players, so that the balls can be set up again and the frame restarted with no change to the score since the last completed frame. This is the result of situations, such as trading of containing safeties, where there is no foreseeable change to the pattern of shots being played, so the frame could go on indefinitely.
In pool, placing of the object balls back in the rack, after a foul break.
Sandbagging, in any handicapped sport, is the unethical practice of deliberately playing below your ability in order to alter your handicap so it does not reflect your true ability.
This is a term used more in snooker to refer to a follow shot, when the cue ball is hit above center to allow it to follow the object ball after impact.