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

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Etymology

Origin of monitor

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

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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

Tajsar said the plaintiffs would closely monitor the government’s compliance with the injunction.

From Los Angeles Times ● Oct. 29, 2026

The system is supposed to monitor train speeds and movements to help prevent collisions by maintaining safe distances between them.

From Barron's ● Oct. 29, 2026

This increased movement could help the immune system monitor for harmful pathogens, including bacteria and viruses.

From Science Daily ● Oct. 28, 2026

Parental controls are a useful tool, helping you to monitor and limit the time your children spend online, and what they do when they're there.

From BBC ● Oct. 27, 2026

Zeke nearly fell off the pillar, but monitor lizards never really fall from things.

From "Chronicles of a Lizard Nobody" by Patrick Ness

A new optical sensor costing just $10 could bring laboratory-level precision to wearable health monitors, potentially allowing people to track blood glucose without needles.

From Science Daily ● Oct. 23, 2026

These are the norms for social engagement on college campuses today—from sober monitors and consent ambassadors, to strict requirements and paperwork to throw campus shindigs.

From The Wall Street Journal ● Oct. 18, 2026

The suit, which seeks unspecified damages, was filed in September 2025, but the federal monitors recently released their report containing key details about the incident.

From Los Angeles Times ● Oct. 16, 2026

Scotland does not declare droughts but monitors "water scarcity" - when there is not enough water of sufficient quality to meet demands of people and the environment.

From BBC ● Oct. 15, 2026

He paused for a moment, and there were cheers in the stadium, which they could see on monitors in the room.

From "City Spies" by James Ponti

From these consoles, teams monitored weather and wind conditions, and issued the all-important “go” if things were right, or “no go” if changes needed to be made.

From Los Angeles Times ● Oct. 28, 2026

Dacic said the suspect has not been identified, but he was a minor and Serbian citizen who was being monitored by security services as he was "known to be a supporter of the Islamic State".

From BBC ● Oct. 28, 2026

They monitored the animals under different lighting conditions to examine their daily activity and rest cycles.

From Science Daily ● Oct. 27, 2026

The victim's family said the shooter was known to the authorities, and demanded to know whether he had been properly monitored.

From Barron's ● Oct. 24, 2026

Mountain Dew was forbidden, and our speech was monitored for the slightest hint of a Raleigh accent.

From "Me Talk Pretty One Day" by David Sedaris

They affected thousands of wells, storage tanks and natural-gas processing plants, and required companies to replace leaky, older equipment and buy new monitoring tools.

From The Wall Street Journal ● Oct. 27, 2026

The vaccine is expected to be approved next year, and analysts are closely monitoring studies evaluating intismeran in patients with renal-cell carcinoma and muscle-invasive bladder cancer who have undergone surgery.

From MarketWatch ● Oct. 26, 2026

Even with the regular monitoring and structured conditions of clinical trials, patients became less consistent about taking their medication as time passed.

From Science Daily ● Oct. 25, 2026

In preparation for the storm, the Department for Infrastructure said their teams have been checking and clearing road gullies, monitoring river levels and tidal surges, and deploying a portion of temporary flood defences.

From BBC ● Oct. 24, 2026

So of course he would be the first person who—and there went the bell to signal the start of lunch—was without a hall pass in the hallway the Hall Monitors were monitoring.

From "Chronicles of a Lizard Nobody" by Patrick Ness

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Related Words

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

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