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

“As always when we have an investigation — external, law enforcement, whatever — we monitor that,” Manfred said.

From Los Angeles Times ● Oct. 24, 2026

That has ignited a societal debate over how best to monitor and regulate the new technology.

From The Wall Street Journal ● Oct. 23, 2026

"He went twice to the ICE facilities… begging them to remove the ankle monitor," he said.

From BBC ● Oct. 21, 2026

The recordings were transmitted to Earth, where researchers could monitor changes in heart function throughout the missions.

From Science Daily ● Oct. 21, 2026

She reaches an arm behind the monitor, pulls out a long sleeve, and unzips it to unveil a shiny red sword with golden Japanese characters inscribed onto the blade.

From "Kwame Crashes the Underworld" by Craig Kofi Farmer

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

The “Cornell 7” case has thrown a spotlight on safety efforts at schools, many of them student-led, like sober monitors and consent officers.

From The Wall Street Journal ● Oct. 22, 2026

The United Nations humanitarian office, which monitors the attacks, says reports of settler violence have risen every year over the past decade, and spiked sharply after the Hamas-led attack on Israel on Oct.

From The Wall Street Journal ● Oct. 17, 2026

“The Department takes the findings and recommendations of the court-appointed Rosas monitors seriously and remains committed to addressing identified concerns through appropriate accountability and corrective measures,” the Sheriff’s Department said in its emailed statement.

From Los Angeles Times ● Oct. 16, 2026

They gathered a group of volunteers and hooked them up to monitors measuring their heart rate and body temperature—the physiological signals of such emotions as anger, sadness, and fear.

From "Blink" by Malcolm Gladwell

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

The trial will continue so that the patients involved can be monitored – both to see if the cancer returns over time and to assess whether the drug ultimately helps them live longer.

From BBC ● Oct. 23, 2026

OpenAI’s Pachocki called the reporting “confused” in a post on X, but raised his own concerns about kick-starting an industrywide race into developing AI models that can’t be monitored.

From The Wall Street Journal ● Oct. 23, 2026

The trial included only 63 participants, and patients were monitored for six months.

From Science Daily ● Oct. 22, 2026

The other voice returned and said the call would be recorded and monitored, and to press 1 if I wanted to proceed.

From "From the Desk of Zoe Washington" by Janae Marks

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

The monitoring program is based at ETH Zurich and the universities of Fribourg and Zurich in Switzerland.

From Science Daily ● Oct. 23, 2026

Despite industry assurances, lawmakers and regulators are monitoring the expanding technology.

From MarketWatch ● Oct. 23, 2026

Satellite monitoring can sometimes show where fires started, said Nusantara Atlas founder David Gaveau.

From Barron's ● Oct. 22, 2026

They roam through the tissues, sensing and monitoring.

From "The Lives of a Cell" by Lewis Thomas

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Related Words

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

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