Advantage rule: A rule permitting a referee to refrain from calling a foul if it appears the call would advantage the offender's team

Attacker: (Flat, Wing, Point, Driver) Also called a "utility player," a versatile player who is a secondary 2-meter defender but who is also capable of playing the hole and driver positions

Attacking team: The team that has control of the ball. In the case of a free ball, the team that last had possession. Opposite of the defensive team. 

Backhand: A deceptive shot or pass flipped backward

Ball: The ball used in water polo weighs between 400-450g (less than a pound) and measures about 0.68m to 0.71m across (26 to 28 inches) for men and 0.65m to 0.67m (25 to 26 inches) across for women

Ball under: One example of an ordinary foul, punished by the opposing team earning a free throw. A player may take or hold the ball underwater when being attacked by an opponent. 

Bathing cap: Colored headgear with individual numbers and ear protectors, used to distinguish the various players on a team as well as to protect the athletes. Caps must be worn for the duration of the match. If a player loses a cap, the player should replace it at the next appropriate stoppage in the game, typically when their own team has possession. 

Brutality: A type of an exclusion foul, punished by the opposing team being awarded a free throw, as well as the offending player being excluded for 20 seconds or until a goal is scored, or until that player's team regains possession. Brutality is a broad term and includes dangerously rough play, such as elbowing an opponent in the face or punching. 

Center back: A defensive player whose main task is to counter the opposition's center forward

Center forward: A team's main attacking player - in the men's games, these players are usually the biggest and strongest - who takes position directly in front of the opponent's goal between the 2-meter and 4-meter lines. This player is also known as the hole man, hole set, or two-meter man. 

Corner throw: A throw used to restart play if a defensive player touched the ball last before it went out over the goal line 

Dead-time: The time between the whistle for a foul and the restart of a play and the clock 

Dead time-foul: Any foul committed during the dead time 

Double dead time foul: Simultaneous fouls that occur by offensive and defensive players during dead time 

Double hole: An offense using two-hole sets, one in front of each post of the goal. This is also known as the double post. 

Dribble: To swim with the ball

Drive: To swim quickly into the space in front of the goal on offense without the ball

Driver: A player, usually a fast swimmer, whose main task is to move the ball into goal-scoring position

Drop: A defensive strategy in which the players drop back to protect the center of the pool and help block shots

Dry pass: A pass made so the receiver can catch it before it hits the water 

Eggbeater: The alternating leg kick used to tread water and lift players vertically out of the water, also known as a flutter kick

Exclusion area: The designated area outside the field of play where excluded players wait to return to the game after their punishment for an exclusion foul

Exclusion foul: A variety of offenses that are punished by awarding a free throw to the opposing team, with the addition of the player who committed the foul being excluded from gameplay for 20 seconds or until a goal is scored or until the player's own team regains possession. Examples of these fouls include: interfering with a free throw, intentionally splashing water in an opponent's face, kicking or striking an opponent, using foul language, showing disrespect for a referee or other official and committing an act of brutality. These fouls are sometimes called "major fouls." 

Faceoff: A throw by a referee giving each team an equal chance to reach the ball following a stoppage where neither team was solely to blame. This is also known as a neutral throw. 

Field player: Any player who is not the goalkeeper

Four-meter foul: A foul by a defensive player inside the four-meter line directly aimed at preventing a goal

Four-meter line: An imaginary line marked with yellow buoys demonstrating 4 meters from each goal line

Five-meter: Both the physical marking on the pool deck, 5 meters out from each goal line and another name for a penalty shot

Free throw: The standard method of restarting play after the ball crosses the sideline or after any foul that does not earn a penalty throw

Front: To defend between the ball and the center forward/ hole set, preventing the hole set from receiving a pass

Goals: Two goal boxes, which float on the water, are 3.0m wide and 0.9m high (10 feet wide by 3 feet high)

Goal throw: A throw by the defending goalkeeper to restart play if an attacking player is the last to touch the ball before it goes out over the goal line

Half distance: An imaginary line marked with white buoys that divides the field of play into two equal halves

Hold: To lift or carry the ball, press it underwater or place the hand over or under the ball

Hole guard: A defensive player who takes position in front of his or her own guard and guards the center forward/ hole set

Impeding: To hinder the movement of a player not in possession of the ball

Inside water: The position of being in front of a defender and moving toward the goal 

Lane press: A defensive strategy where players are positioned in the passing lanes, or between the ball and the players they are guarding, instead of between the offensive players and the goal

Lane ropes and buoys: Used to distinguish the field of play and imaginary distances from the goals

Live time: When the clock is running

Man down: A 20-second period of time for the defensive team where it plays with one less player than the offense after a defensive player commits an exclusion foul

Man up: A 20-second period of time for the offensive team where it has one more player than the defensive team after a defensive player commits an exclusion foul

Moving pick: A move by an offensive player to swim in front of a player defending another offensive player, freeing that teammate for a pass or shot 

Ordinary foul: A variety of offenses that are punished by the opposing team earning a free throw from the point of the foul. If a defending player commits an ordinary foul within the 2-meter area, the free throw is taken from the 2-meter line. Examples of these fouls include: holding onto the goal posts, holding the entire ball underwater, hitting the ball with a clenched fist (the goalkeeper is allowed to do this within five meters of the goal), touching the ball with both hands at the same time (the goalkeeper is allowed to do this), impeding the free movement of an opponent who is not holding the ball, pushing an opponent and wasting time. These fouls are sometimes called "common fouls" and are responsible for approximately 90% of all whistle activity from the referees. 

Penalty foul: A variety of fouls that are punished by the opposing team being awarded a penalty throw from behind the 5-meter line. Any member of the team awarded the penalty throw may take the shot. Examples of these fouls include: committing a foul within 5 meters of the goal a player is defending if the referee decides that the foul prevented a likely goal, an act of brutality committed within 5 meters of the goal and tipping the goal box to prevent what likely would have been a scoring shot. If a penalty throw rebounds off the goal or the goalkeeper, play resumes. 

Penalty throw: A throw from the 4-meter line by a member of the attacking team, defended by only the goalkeeper, after a penalty foul against a defending player

Personal foul: An exclusion foul or penalty foul recorded against a player

Point: The position on offense that is farthest from the goal in the 12 o'clock position

Press: To extend the defense beyond its normal range to increase the pressure on each offensive player

Red: The period of time immediately prior to the expiration of the shot clock or game clock. Some teams yell "red" when either of these clocks indicates 10 seconds or less. 

Re-entry area: The area closest to the team bench beyond the goal demarked in red and most commonly used as the penalty area. Teams may substitute on the fly from the re-entry area. 

Release: A free throw by the center, passed to a teammate on the perimeter

Seven-meter line: An imaginary line marked with green buoys 7 meters away from each goal line

Shot Clock: A side has a maximum of 30 seconds to possess the ball before attempting a shot on the opponent’s goal

Sink: To push a player under the water during a tackle

Splashing: A variety of an exclusion foul, punished by the opposing team being awarded a free throw, as well as the offending player being excluded for 20 seconds or until a goal is scored, or until that player's team regains possession. Splashing is typically called for deliberately splashing water in an opponent's face. 

Stalling: A type of ordinary foul, punished by the opposing team earning a free throw. Stalling is called when a team fails to shoot or advance the ball within 35 seconds

Stationary pick: A move by an offensive player to stop in the path of a player defending a teammate, freeing that teammate for a pass or shot

Swim-off: A race for the ball in the center of the pool to start each period 

Swimsuits: The players' uniforms should be non-transparent or have a separate undergarment 

Two-meter violation: A type of ordinary foul, punished by the opposing team earning a free throw

Wet pass: A pass from one player to another that is designated to land in the water