monitor

One that admonishes, cautions, or reminds, especially with respect to matters of conduct.

A pupil who assists a teacher in routine duties.

A usually electronic device used to record, regulate, or control a process or system.

A video display or speaker used in a production studio to check audio or video quality.

A device that accepts video signals from a computer and displays information on a screen; a video display.

A program that observes, supervises, or controls the activities of other programs.

An articulated device holding a rotating nozzle with which a jet of water is regulated, used in mining and firefighting.

A heavily ironclad warship of the 19th century with a low, flat deck and one or more gun turrets.