An airspace in which aircraft, especially military aircraft, are forbidden to fly.

zone melting

(physics, chemistry) A technique used to purify a metal, semiconductor or other solid in which a heating system slowly causes a series of molten zones to traverse the solid, leaving purer material behind it.

(basketball, soccer) A defense in which each player covers an area of the court.

A range of longitudes where a common standard time is used.

A geographic area in which some sanctioning authority prohibits specific activities, see also Restricted Area.

(baseball) The area through which if a pitched ball passes, it will be called a strike, typically from the batter's knees to the belt and the width of home plate.

(American football) A zone between the defensive line of scrimmage and the offensive line of scrimmage.

(cycling) A designated place along the course of a bicycle race where it is permitted for the riders to receive food and energy drinks from their team support personnel.

The part of the near-surface body of an ocean or lake that receives enough sunlight for photosynthesis to be possible.