monitor

/ˈmɒnɨtə/

noun

1
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.”
2
A device that detects and informs on the presence, quantity, etc., of something.
3
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.”
4
A studio monitor or loudspeaker.
5
A program for viewing and editing.
“a machine code monitor”
6
A student leader in a class.
7
One of a class of relatively small armored warships designed for shore bombardment or riverine warfare rather than combat with other ships.
8
An ironclad.
9
A monitor lizard.
10
One who admonishes; one who warns of faults, informs of duty, or gives advice and instruction by way of reproof or caution.
11
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.
12
A monitor nozzle.