monitor

Someone who watches over something; a person in charge of something or someone.

The camp monitors look after the children during the night, when the teachers are asleep.

A device that detects and informs on the presence, quantity, etc., of something.

(computing) A device similar to a television set used as to give a graphical display of the output from a computer.

The information flashed up on the monitor.

A studio monitor or loudspeaker.

(computing) A program for viewing and editing.

a machine code monitor

(dated)(computing, dated) The command line interface of an operating system.

(Hong Kong, Singapore, archaic)(Hong Kong, Singapore, archaic in British) A student leader in a class.

(nautical) A relatively small armored warship with only one or two turrets (but often carrying unusually large guns for a warship of its size), usually designed for shore bombardment or riverine warfare rather than open-ocean combat.

A monitor lizard (Varanus spp. and extinct relatives in family Varanidae).

(engineering) A tool holder, as for a lathe, shaped like a low turret, and capable of being revolved on a vertical pivot so as to bring several tools successively into position.

A monitor nozzle.

(obsolete)One who admonishes; one who warns of faults, informs of duty, or gives advice and instruction by way of reproof or caution.

c. 1620, Francis Bacon, letter of advice to Sir George Villiers You need not be a monitor to your gracious master the king.

(transitive)To watch over; to guard.

2002, Mark Baker, Garry Smith, GridRM: A Resource Monitoring Architecture for the Grid, in Manish Parashar (editor), Grid Computing - GRID 2002: Third International Workshop, Springer, LNCS 2536, page 268, A wide-area distributed system such as a Grid requires that a broad range of data be monitored and collected for a variety of tasks such as fault detection and performance monitoring, analysis, prediction and tuning.