Meaning

• 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.

• 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.

• A program for viewing and editing.

  "a machine code monitor"

• A student leader in a class.

• One of a class of relatively small armored warships designed for shore bombardment or riverine warfare rather than combat with other ships.

• An ironclad.

• A monitor lizard.

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

• 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 the several tools successively into position.

• A monitor nozzle.

Meaning

• To watch over; to guard.