Definition of Chalk

A two-piece cue constructed to resemble a house cue, with a near-invisible wood-to-wood joint. The subterfuge often enables a hustler to temporarily fool unsuspecting fish into thinking that he or she is an unskilled banger with no regard for finesse or equipment quality. Many league players also use cheap but solid sneaky petes as their break cues.

Slang for the cue ball.

Netted or cupped pockets that do not return the balls to the foot end of the table by means of a gutter system or sloped surface beneath (they must instead be retrieved manually).

A shot in which the cue ball is potted after caroming off another ball. In snooker and most pool games doing this would be a fault (foul), but the move will score points in many games in which hazards (as such) apply, such as English billiards, or in the final or game point in Cowboy pool. The term derives from this hazard costing the player points in early forms of billiards.

In snooker, after particular fouls are committed, the referee can call a "free ball." This allows the next player to assign any ball as "ball on" if he or she is shooting next.

The ball required to guarantee victory in a match. Sometimes used figuratively to mean the last difficult ball required (chiefly British and usually used in multi-frame matches, particularly snooker).

A Baulk line is line drawn across the table 29 inches from the bottom cushion and parallel to that cushion.

Same as cloth (deprecated; it is factually incorrect).

When two objects balls are lined up so that you aim to pocket the nearest object ball, the second object ball will pocket. "That was an easy combination shot, the six ball was wired to the four ball". Also wired combination/combo, wired kiss.

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.

This refers to a shot that is not banked, does not hit a rail and goes into the pocket without contacting any other balls on the table.

This refers to the distance of deflection that the ball comes off of the cue stick after a hit is applied with side spin on it.

The pocket in snooker that is closest to the green spot.

Principally US: One or more sets, usually in the context of gambling. See also ahead race (a.k.a. ahead session) for a more specialized usage.
Principally British: Any of a group of pre-determined frames played in a match too long to be completed within a single day's play. A best of 19 frame match, for example, is generally played with two "sessions", the first composed of nine frames, the second of ten. This term is generally used only in the context of professional snooker, as matches at the amateur level are rarely played over more than nine frames. Longer matches can be split into three or four sessions.
In the APA and CPA Leagues, session refers to the season in which League play took place. There are three sessions in each League Year-Summer Session, Fall Session and Spring Session.

Verb: "To Clock" To carefully note the abilities or betting inclinations of other players for future reference.

Chiefly Australian: Same as a force follow shot.

A break shot in which the object is to leave the incoming player with no shot or a very difficult shot, such as is normally employed in the opening break of straight pool. Cf. open break.

A gentle tap of the cue ball with the intention of getting it as tight as possible behind another ball, in the hope of a snooker. It is most common in the game of snooker, and is illegal in many pool games, in which on every shot a ball must either be pocketed, or some ball must contact a cushion after the cue ball has contacted an object ball.

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.

To apply chalk to the tip of your cue before a shot.

A pejorative term for an improper rack in which the balls are not properly in contact with their neighbors, often resulting in a poor spread on the break.

Also highs, high balls, high ones. In eight-ball and related games, to be shooting the striped suit (group) of balls (9 through 15); "you're high balls" or "I've got the highs" ("you're high" is rare, because of the "intoxication" ambiguity). Compare stripes, yellows, big ones, overs; contrast low.

Shooting at an object ball that is already in motion at the moment of shooting and cue ball impact; illegal in most games and usually only seen in exhibition/trick shots.

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.