sector

A part or division, as of a city or a national economy.

The portion of a circle bounded by two radii and the included arc.

A measuring instrument consisting of two graduated arms hinged together at one end.

A portion of a magnetic storage device making up the smallest addressable unit of information.

A division of a defensive position for which one military unit is responsible.

A division of an offensive military position.

To divide (something) into sectors.

A cutting implement or device.