Definition of Mushroom

This is a simple method of gambling where bets are determined between each game instead of playing matches.

Australian: Defeated with all seven of one's object balls (in blackball or eight-ball) remaining on the table.

Describing a situation where a pot is made more difficult, either by a pocket being partially blocked by another ball so that not all of it is available, or the cue ball path to the object ball's potting angle involves going past another ball very closely.

Similar to run out, but more specific to making all required shots from the start of a rack. Also known as also break and run or break and dish.

One of the alternating turns players (or doubles teams) are allowed at the table, before a shot is played that concedes a visit to his/her opponent (e.g. "he ran out in one visit"). Usually synonymous with inning as applied to a single player/team, except in scotch doubles format.

As in many other sports, "legal" means not causing or likely to cause a foul (the opposite being illegal). A legal hit is one in which the requirements for a non-foul hit are met (e.g., in nine-ball, the lowest-numbered ball on the table was hit by the cue ball first, and at least one object ball was pocketed, or any ball reached a cushion, after the hit on the first object ball.). A legal shot is one in which no foul of any kind was involved (e.g. there was not a double hit by the cue, the player's bridge hand did not move a ball, etc.). A legal stroke is one in which the cue stroke obeyed the rules (e.g. the shooter did not perform an illegal jump shot by scooping under the cue ball with the cue tip). A legal ball is a ball-on, an object ball at which it is permissible for the player to shoot. And so on. The term can be used in many ways consistent with these examples ("legal pocket" in one-pocket, "legal equipment" under tournament specifications, etc.).

An area defined on a billiard table, in games such as pool, snooker, English billiards and bagatelle, by a single balkline (drawn or imaginary) that runs across the table near the head (bottom) end; exactly where depends upon table type and size. This balk is where the cue ball is placed in lagging for lead, for making the opening break shot, and sometimes for other purposes, depending upon the game.

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.

A thin sheet of rigid material in the size and shape of a physical ball rack (e.g. a diamond for nine-ball), with holes drilled though it, which is used to make permanent divots in the cloth of the table, one at a time for each ball in the racking pattern, by placing a ball in one of the holes in the carefully placed template and tapping it sharply from above to create the cloth indentation. The holes are spaced slightly closer than the regulation ball width of 21/2 inch (57.15 mm) apart, so that when the balls settle partially into their divots, the outer sides of these indentations create ball-on-ball pressure, pushing the balls together tightly. The purpose of the template is to do away with using a physical rack, with racking instead being performed simply by placing the balls into position, and the divots aligning them into the tightest possible formation automatically. This prevents accidental loose racks, and also thwarts the possibility of cheating by carefully manipulating the ball positions while racking. The European Pocket Billiard Federation (EPBF, Europe's WPA affiliate organization) has adopted this racking technique for its professional Euro-Tour event series.

Also known as 14.1 continuous pool. This game is played on a pocketed table with the fifteen object balls and a cue ball. Every shot must begin with a call, and if made, you get to continue calling shots. The idea is to reach a predetermined score before your opponent. When all but one ball remains, the rack is started over without the apex ball in position, and the last shot is called in such a way as to break the new rack and continue play.

To "give someone weight" is to give them a handicap so the game is more even in skill level. If one player is significantly better than the other in a game, then you can add some weight, more or less balls for someone, to even the difficulty load between each player.

Also double-century break. In English billiards, a break of 200-299 points (i.e. double a century). Larger multi-centuries are regularly achieved. Rare in amateur play, triple centuries are routine, and quadruples not uncommon at World Professional Billiards Championships; 2007 winner Mike Russell shot four triples in the final round alone, while of sixteen competitors, three shot quadruple centuries (one once, one twice, and Russell three times). Quintuple centuries are rare even at the professional level, with only the 494 shot by nine-time World Champion Russell (who has more such titles than any other player in history as of 2007) coming close in that event. World Champion Geet Sethi holds the world record, at a duodectuple century (and then some) of 1276 consecutive points."

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 a ball is given as a handicap it often must be called (generally tacit). A wild handicap means the ball can be made in any manner specifically without being called.

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.

On a shot, the extension of the cue stick through the cue ball position during the end of a player's stroke in the direction originally aimed.

Any system for banking or kicking balls multiple rails which uses table diamonds as aiming references.

Ten Ball is a rotation is a rotation game very similar to nine-ball, using ten balls instead of nine, and with the 10 ball instead of the 9 as the "money ball".
The object of the game is pocket the 10-ball on any legal shot.

Using knowledge of the game and one's own abilities and limitations to choose the manner of shooting and the particular shot from an array presented, that has a degree of likelihood of success. This often requires a player to forego a shot that if made would be very advantageous but does not have a high likelihood of success, in favor of a safety or less advantageous shot that is more realistically achievable.

In snooker, the pocket nearest the yellow spot.

A type of nurse used in carom billiards games. With one object ball frozen to a cushion and the second object ball just slightly away from the rail, the cue ball is gently rebounded across the face of both balls, freezing the away ball to the rail and moving the frozen ball away the same distance its partner was previously, resulting in an identical but reversed configuration, in position to be struck again by the cue ball from the opposite side.

Same as foot spot. Chiefly British today, but also an American usage ca. World War I.

Used when describing perfect play. "as if the balls had strings on them"

Also pills, tally balls and shake balls. Small, round markers typically numbered 1 through 15 or 16, which are placed in a bottle for various random assignment purposes, such as in a tournament roster, to assign order of play in a multiplayer game, or to assign particular balls to players in games such as kelly pool.