An area in a field of crops where the stalks have been flattened into a circle or other geometric shape.

Instrument for measuring azimuths. It is a graduated circle on a sight, gun carriage, searchlight, etc.

(mathematics) The problem, proposed by ancient Greek geometers, of using a finite ruler-and-compass construction to make a square with the same area as a given circle.

a circle formed by a plane that cuts a sphere not through its centre

(netball) One of two semicircles in the goal thirds, radius 4.9 metres, in which the goal shooter and goal attack can shoot.

present participle of square the circle

(philately) A cancellation mark consisting of an outer ring of concentric circles, cropped into a square shape.

(sports, boxing, wrestling, professional wrestling) The boxing or wrestling ring.

(geometry) A circle of radius 1. / (trigonometry, the unit circle) The circle of radius 1 with centre at the origin, used in defining trigonometric functions.

(soccer) The circle in the centre of the pitch which, at kick-off, the defending team may not enter until the attacking side has touched the ball.