monitor

American  

[mon-i-ter] / ˈmɒn ɪ tər /

noun

• monitors
  plural

1. (especially formerly) a student appointed to assist in the conduct of a class or school, as to help take attendance or keep order.

2. a person appointed to supervise students, applicants, etc., taking an examination, chiefly to prevent cheating; proctor.

3. a person who admonishes, especially with reference to conduct.

4. something that serves to remind or give warning.

5. a device or arrangement for observing, detecting, or recording the operation of a machine or system, especially an automatic control system.

6. an instrument for detecting dangerous gases, radiation, etc.

7. Radio and Television.

   1. a receiving apparatus used in a control room, especially to provide a steady check of the quality of an audio or video transmission.

   2. a similar apparatus placed in various parts of a studio so that an audience can watch a recorded portion of a show, the performer can see the various segments of a program, etc.

   3. any such receiving apparatus used in a closed-circuit system, as in an operating room.

8. Computers.

   1. the screen component of a computer, especially a free-standing screen.

   2. a control program.

   3. a group of systems used to measure the performance of a computer system.

9. Nautical.

   1. a former U.S. steam-propelled, armored warship of very low freeboard, having one or more turrets and used for coastal defense.

   2. (initial capital letter, italics) the first of such warships, used against the Confederate ironclad warship Merrimac at Hampton Roads, Va., in 1862.

10. a raised construction straddling the ridge of a roof and having windows or louvers for lighting or ventilating a building, as a factory or warehouse.

11. an articulated mounting for a nozzle, usually mechanically operated, which permits a stream of water to be played in any desired direction, as in firefighting or hydraulic mining.

12. Also called giant. (in hydraulic mining) a nozzle for dislodging and breaking up placer deposits with a jet of water.

13. any of various large lizards of the family Varanidae, of Africa, southern Asia, the East Indies, and Australia, fabled to give warning of the presence of crocodiles: several species are endangered.

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verb (used with object)

• monitors,
  present (3rd person singular)
• monitored,
  past participle,  past
• monitoring
  present participle

1. Radio and Television.

   1. to listen to (transmitted signals) on a receiving set in order to check the quality of the transmission.

   2. to view or listen to (television or radio transmissions) in order to check the quality of the video or audio.

   3. to listen to (a radio conversation or channel); keep tuned to.

2. to observe, record, or detect (an operation or condition) with instruments that have no effect upon the operation or condition.

3. to oversee, supervise, or regulate.

   to monitor the administering of a test.

4. to watch closely for purposes of control, surveillance, etc.; keep track of; check continually.

   to monitor one's eating habits.

verb (used without object)

• monitors,
  present (3rd person singular)
• monitored,
  past participle,  past
• monitoring
  present participle

1. to serve as a monitor, detector, supervisor, etc.

monitor British  

/ ˈmɒnɪtə /

noun

1. a person or piece of equipment that warns, checks, controls, or keeps a continuous record of something

2. education

   1. a senior pupil with various supervisory duties

   2. a pupil assisting a teacher in classroom organization, etc

3. a television screen used to display certain kinds of information in a television studio, airport, etc

4. the unit in a desk computer that contains the screen

5. 1. a loudspeaker used in a recording studio control room to determine quality or balance

   2. a loudspeaker used on stage to enable musicians to hear themselves

6. a device for controlling the direction of a water jet in fire fighting

7. any large predatory lizard of the genus Varanus and family Varanidae, inhabiting warm regions of Africa, Asia, and Australia See also Komodo dragon

8. Also called: giant. mining a nozzle for directing a high-pressure jet of water at the material to be excavated

9. (formerly) a small heavily armoured shallow-draught warship used for coastal assault

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verb

1. to act as a monitor of

2. to observe or record (the activity or performance) of (an engine or other device)

3. to check (the technical quality of) (a radio or television broadcast)

monitor Scientific  

/ mŏn′ĭ-tər /

1. A device that accepts video signals from a computer and displays information on a screen. Monitors generally employ cathode-ray tubes or flat-panel displays to project the image.

2. See Note at pixel

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Other Word Forms

Derived Forms

• monitorship
  noun
• monitress
  noun
• monitorial
  adjective
• self-monitoring
  adjective
• unmonitored
  adjective
• monitorially
  adverb

Inflected Forms

Nouns

• monitors
  plural

Participles

• monitoring
  present
• monitored
  past

Conjugated Forms

Present

• monitor
  simple
• monitors
  simple
• have monitored
  perfect
• has monitored
  perfect
• am monitoring
  progressive
• are monitoring
  progressive
• is monitoring
  progressive
• have been monitoring
  perfect progressive
• has been monitoring
  perfect progressive

Past

• monitored
  simple
• had monitored
  perfect
• was monitoring
  progressive
• were monitoring
  progressive
• had been monitoring
  perfect progressive

Future

• will monitor
  simple
• will have monitored
  perfect
• will be monitoring
  progressive
• will have been monitoring
  perfect progressive

Etymology

Origin of monitor

First recorded in 1540–50; from Latin: “prompter, adviser,” equivalent to monit(us) “reminded” (past participle of monēre) + -or -or

Explanation

A monitor is a device or a person who watches or checks to see that all is going well. If you're babysitting, you might use a baby monitor so you can hear if the baby cries in its sleep. Monitor can be used as a noun or a verb, both of which are concerned with watching over someone or something. A heart monitor displays the rhythm of your heart. A hall monitor is a person who checks to see that students aren't wandering the halls. If you are monitoring your grades, you are keeping track of them to see if they go up or down. And some parents buy a program that will monitor your Internet use, though you might think that this is an invasion of privacy.

Example Sentences

See Examples For:

monitor monitors monitored monitoring

We were given rare access to an underground bunker in Kyiv, dubbed – appropriately enough – the "Iron Command Centre", where railway staff monitor threats in real time.

From BBC ● Oct. 6, 2026

“Remember, there are officers who are professional and we cannot judge all officers by one’s actions, but I will continue to monitor this investigation.”

From Los Angeles Times ● Oct. 6, 2026

The non-invasive technique uses reflected light to create high-resolution, cross-sectional images of biological tissues, particularly the retina and optic nerve, allowing doctors to detect and monitor disease.

From Barron's ● Oct. 5, 2026

A corruption scandal last decade, before Mr. Fain took office, culminated in convictions of 11 UAW officials and a federal court appointment of an independent monitor.

From The Wall Street Journal ● Oct. 4, 2026

It’s mostly run by Manifestors, and they monitor Remarkables to make sure we don’t mess with Unremarkables.

From "The Manifestor Prophecy" by Angie Thomas

Inside a dimly lit room, participants slept with monitors attached to their heads, some cradling stuffed toys in their beds.

From Barron's ● Oct. 6, 2026

Speaking at the press launch, Winkleman said she is totally focused on the celebrities while she's in the castle, and is glued to the monitors showing footage of them throughout the day.

From BBC ● Oct. 1, 2026

But Elizabeth Lafontaine, director of research at Placer.ai, a firm that monitors retail foot traffic, said Target’s announcement seems intended to build on newfound momentum.

From MarketWatch ● Sep. 29, 2026

Their goal isn’t to make monitors play catchy tunes, Schlesinger says, but to make alarms easier to distinguish, less irritating and more informative.

From The Wall Street Journal ● Sep. 28, 2026

After several agonizing moments of screen snow, the monitors jumped and settled.

From "Artemis Fowl" by Eoin Colfer

The doses and treatment used in the clinical trial are being carefully controlled and monitored by medical professionals.

From Science Daily ● Oct. 4, 2026

ADP's data is closely monitored ahead of official employment numbers due Friday, although the reports can diverge.

From Barron's ● Sep. 30, 2026

In clinical settings, participants are screened, monitored and supported before, during and after treatment.

From BBC ● Sep. 29, 2026

Students who leave the program will be monitored for four years, a safety net meant to keep students who still need help with English skills.

From Los Angeles Times ● Sep. 28, 2026

Among the members of the inspection task force, Lawrence and Mills were willing to entertain the idea of a test ban in principle but were pessimistic that it could be adequately monitored.

From "Big Science" by Michael Hiltzik

For decades, the S&P 500 has been the preferred benchmark for monitoring the performance of the U.S. stock market.

From The Wall Street Journal ● Oct. 6, 2026

Jen Eaves has been taking a slower approach to her mother’s cognitive decline, even though she’s the vice president of marketing for Aura, an identity-theft monitoring service.

From MarketWatch ● Oct. 6, 2026

In 2023, NHS England wrote to mental health trusts saying monitoring technology should not be introduced as a blanket approach and decisions should be made for each patient individually.

From BBC ● Oct. 6, 2026

US Secretary of State Marco Rubio said Tuesday that Washington was closely monitoring the situation and called for Russia to be "transparent".

From Barron's ● Oct. 6, 2026

The United Nations Security Council had passed a new resolution to tighten the monitoring and enforcement of sanctions against the Taliban.

From "Shooting Kabul" by N. H. Senzai

Related Words

• audit
• check
• control
• follow
• keep an eye on
• observe
• oversee
• scan
• supervise
• survey
• track