Definition of the d

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.

24 Random Essential Billiards Terms

A shot where the cue ball must hit the object ball so as to make it travel out of a straight line, at a different angle, toward its destination.
The 5 out (meaning the player getting the handicap can win by making the 5, 6, 7, 8 or 9 balls).

1- Applying very powerful follow on the cue ball thereby causing the maximum amount of follow.

2- A powerful follow shot with a high degree of top spin on it; usually when the object ball being hit is relatively close to the cue ball and is being hit very full; also known as "prograde top spin" or "prograde follow" (when referring to the action on the shot rather than the shot per se), and as a "jenny" in Australia.

This piece of armament keeps the butt of your cue safe from coincidental contact with the floor or other damaging incidents. It is usually made of a rubber composite or other durable or flexible material to absorb impact in the case of a collision.
Also straight eight-ball. Same as bar pool. Not to be confused with the games of straight pool or straight rail.
This is a slang term created by Freddy Bentivegna to refer to a cluster of balls on your side of the table that do not lend to easy pocketing in a game of one pocket.
This is the act of keeping your ball location advantages the way they are, and not allowing your opponent to even things out in the game of one pocket.
When the object ball lies behind another ball which makes it impossible to be struck by the cue with a direct hit.
Be in a game where either because of disparity in skill level, or because of a handicap given, it would be very difficult to lose.
Chiefly American: The half of the table from which the break shot is taken. This usage is conceptually opposite that in British English, where this end of the table is called the bottom. Contrast foot. See also kitchen.
This is a special shaped leather or plastic bottle that is used on the table during play in special pocket games.
This a shot that hits the object ball at the nine ball to see if you can get lucky by sinking the nine ball in any pocket. (also see Cheese the Nine and Rolling the Cheese).
Also lady's aid or girly stick. A denigrating term for the mechanical bridge.
A player skilled at very thin cut shots, and shots in which a ball must pass cleanly through a very narrow space (such as the cue ball between two of the opponent's object balls with barely enough room) to avoid a foul and/or to pocket a ball. Such shots may be referred to as "surgery", "surgical shots", "surgical cuts", etc. (chiefly US, colloquial). See also feather (US) or snick (UK).
Hitting the object ball with not enough of a cut angle; hitting the object ball too full or "fat". It is a well-known maxim that overcutting is preferable to undercutting.
Also money-added. Said of a tournament in which the pot of money to pay out to the winner(s) contains sponsor monies in addition to competitor entry fees. Often used as an adjective: "a money-added event".
When a player is on the receiving end of a devastating safety where it is very difficult or near impossible to make a legal hit on an object ball.
The white ball struck by the cue (and so used to strike other colored, numbered, object balls) during play.
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."
(Chiefly British.) In snooker and blackball/eight-ball pool, an instance where the cue ball has been potted (pocketed) after contacting an object ball. It is a fault (foul) in most games. There is no equivalent (current) American term for this specific means of pocketing the white ball. Compare losing hazard, scratch.
The break box is a zone in the "kitchen" of the head (British: bottom) of the table, from which the break shot must be taken with the cue ball,
A short, jabbed draw stroke usually employed so as to not commit a foul (i.e. due to following through to a double hit) when the cue ball is very near to the target object ball.
Common slang in the US for a cheap, poorly made cue. Compare wood.
Chiefly American: The short rail at the head of the table. Traditionally this is the rail on which the table manufacturer's logo appears. Compare bottom rail, baulk rail; contrast foot rail.