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, ˌmɒnɪˈtɔːrɪəl /

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

Lytvynenko and her colleagues constantly monitor social media to learn about threats.

From BBC ● Aug. 8, 2026

Experts at Chilbolton Observatory, operated by the UK's national space laboratory RAL Space, monitor UK-licenced satellites and fast-multiplying fragments of space debris swirling around them.

From Barron's ● Aug. 7, 2026

Spanish and Italian agencies watching inbound migratory flows have to monitor the Sahara—a desert larger than the European Union—and the Mediterranean’s broad blue waterway.

From The Wall Street Journal ● Aug. 7, 2026

These devices allowed researchers to monitor changes in everyday social patterns without substantially disrupting the crew's routines.

From Science Daily ● Aug. 7, 2026

Besides keeping people farther away from harm, a big advantage of this is the ability to monitor a greater number of places.

From "Mountain of Fire" by Rebecca E. F. Barone

Officials said they have upgraded air monitors at nearby Eastman Avenue Elementary School to screen for hydrogen sulfide, methane and ammonia — all byproducts of rotting food.

From Los Angeles Times ● Aug. 6, 2026

An international team of atmospheric scientists and wildfire specialists monitors these unusual clouds.

From Science Daily ● Aug. 5, 2026

UN human rights monitors have voiced concern about rising numbers of civilian casualties, which have reached their highest level since Russia's invasion in February 2022.

From Barron's ● Aug. 5, 2026

Computer parts have to work hard to power sessions for the more than three billion people who play videogames, creating often-intricate worlds displayed on large monitors.

From The Wall Street Journal ● Jul. 30, 2026

The white-noise machine under the window dulled the beeping of the monitors next to the bed.

From "Made You Up" by Francesca Zappia

Laforteza’s progress will be monitored and she’ll be reassessed in September — just as the group is slated to kick off their world tour.

From Los Angeles Times ● Aug. 8, 2026

The giant space rocks are generally monitored by optical sensors, as they are too far away for Chilbolton's radar dish to detect.

From Barron's ● Aug. 7, 2026

Honeybees were trained to visit the feeders, and the team monitored their behavior over several days.

From Science Daily ● Aug. 6, 2026

A spokesman added: "All pet parasite treatments undergo rigorous scientific assessment by independent regulatory authorities before approval for use, and their safety and efficacy continue to be monitored."

From BBC ● Aug. 5, 2026

According to the training film, this device monitored my physical location and also granted or denied me access to different areas of the IOI office complex.

From "Ready Player One: A Novel" by Ernest Cline

The research team plans to continue monitoring the participants as they enter young adulthood.

From Science Daily ● Aug. 8, 2026

Japan and South Korea are closely monitoring the possibility of additional launches by North Korea while analyzing the ballistic missile’s flight distance, Seoul’s defense ministry said on Thursday.

From The Wall Street Journal ● Aug. 7, 2026

In the sweeping shadow of a satellite dish, staff at the Chilbolton Observatory in southern England track a growing number of objects in Earth's orbit, providing data that underpins Britain's space monitoring efforts.

From Barron's ● Aug. 7, 2026

In a report to executive, external, the fall in numbers had been attributed to a change in booking system which officers said would "require further monitoring".

From BBC ● Aug. 6, 2026

Foaly was a paranoid centaur, convinced that human intelligence agencies were monitoring his transport and surveillance network.

From "Artemis Fowl" by Eoin Colfer

Related Words

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