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

When the rules of the opening break are broken. Ex: If not enough balls contact with rails off the break.
Same as cheating the pocket. Principally used in snooker.
Principally British: In snooker, if a player wins a match without the need for the final session to be played (for example, if a player wins a best-of-25-frames match split into three sessions - two sessions of eight frames and one of nine - by a margin of say, 13 frames to 3), then they are said to have won the match "with a session to spare".
Toward the foot of the table.
This is a term used in slang to reference the bridge tool.
The triangular device, generally plastic, used to group the balls in a pyramid form prior to the beginning of a game.
To win an inning that counters a good game your opponent just won.
The inning win that counters a good game your opponent just won.
Same as mechanical bridge; so-called because of its typical shape.
Side spin on a cue ball on the opposite side of the direction of the cut angle to be played (right-hand english when cutting an object ball to the left, and vice versa). In addition to affecting cue ball position, outside english can be used to decrease throw.
Jargon for a tournament chart, showing which players are playing against whom and what the results are. Often shortened to card.
See overcut.
This game is played on a smaller octagonal table filled with bumpers in the middle and two more bumpers surrounding a hole on each side of the table. The game is played by trying to sink the balls into the opposite pocket by hitting the object ball directly instead of using a cue ball.

1- Pocketing of the cue ball in pocket billiards. In most games, a scratch is a type of foul. "Scratch" is sometimes used to refer to all types of fouls.

2- British term/slang for Draw

Toward the head of the table. This is the playing area on the table above the middle pockets. The idea in an up table game is that shots are more difficult and further from the pockets in one pocket pool.
Also tiptool, tip-tool. Any of a class of maintenance tools for cue tips, including shapers, scuffers, mushroom trimmers, tappers, burnishers and tip clamps. Road, league and tournament players often carry an array of tip tools in their cases. The term is generally not applied to cue chalk.
The forward rotation of the cue ball that results from a follow shot. Also known as top spin or top, follow is applied to the cue ball by hitting it above its equator, causing it to spin more rapidly in the direction of travel than it would simply by rolling on the cloth from a center-ball hit. Follow speeds the cue ball up, and widens both the carom angle after contact with an object ball, and angle of reflection off a cushion.
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.
Also spider rest. A type of rest, similar to a common American-style rake bridge but with longer legs supporting the head so that the cue is higher and can reach over and around an obstructing ball to reach the cue ball. See also swan.
In one pocket pool this means that you change your play based on where the count is during the game. If you are ahead you might choose more conservative shots, and if you are behind you could choose more aggressive shots.
In snooker, the colour ball worth 5 points, whose spot is at the center of the table.
Also swan rest. A type of rest, similar to a spider in that the head is raised by longer supporting legs, but instead of a selection of grooves on the top for the cue to rest in there is only one, on the end of an overhanging neck, so that a player can get to the cue ball more easily if the path is blocked by two or more obstructing balls. Also known as the goose neck.
A shot aimed so that the center of the cue ball is in line with the edge of the object ball, eclipsing half of the ball. "Hit it just a little thinner than half-ball." Assuming a cling does not occur, the shot will impart post-contact momentum on the object ball in a direction 30° (which is arcsin(1 - x), where x is the fraction of object ball eclipsed: ½ in this case) off the direction of the cue-ball's pre-contact momentum. Also notable because the carom angle the cue ball takes is more consistent than at other contact points.
This is a table that offers poor conditions for play; it is either dirty, wet, or overall poor quality.
This is a player who has the ability to make difficult shots in one pocket, because they are likely proficient at other pool games first.