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

That’s according to Goldman Sachs’ hedge fund trend monitor that published Thursday and encompasses almost 1,000 funds with $5.4 trillion of gross equity positioning.

From MarketWatch ● Aug. 21, 2026

The next morning, the judge named attorney Andrea Sheridan Ordin as special master and Dr. Paul H. Wise as independent monitor to enforce the agreement, over the objections of federal officials.

From Los Angeles Times ● Aug. 19, 2026

Moy believes the council should have done more to monitor his son's killers.

From BBC ● Aug. 19, 2026

Brands, she said, “have no way to then really monitor or measure the output, because they’ve had to go in with a patchwork approach, and it doesn’t always ladder to what their ultimate strategy is.”

From The Wall Street Journal ● Aug. 18, 2026

For Hoover, that included getting his agents—often called G-men—to monitor left-wing activists.

From "The Woman All Spies Fear" by Amy Butler Greenfield

Beneath the market’s daily surface, algorithmic money is always in motion, sliding out of one corner and into another as the signals it monitors shift.

From The Wall Street Journal ● Aug. 11, 2026

According to the US Geological Survey, which monitors earthquakes around the world, the epicentre of Monday's quake was 5km east of the village of San José del Palmar.

From BBC ● Aug. 10, 2026

The South Tyrol Museum of Archaeology oversees the preservation of the mummy and continuously monitors its condition.

From Science Daily ● Aug. 7, 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

On the other side of a large window, Hype sits at a table that’s crowded with computer monitors, microphones, and headphones.

From "On the Come Up" by Angie Thomas

The peacock’s prognosis is good and he will be monitored for several days more, McManus said.

From Los Angeles Times ● Aug. 20, 2026

They have also monitored 21-year-old forward Kenan Yildiz from Juventus.

From BBC ● Aug. 20, 2026

Numerous police and military vehicles from both countries traveled along the Rio Grande, a natural border closely monitored by the US.

From Barron's ● Aug. 13, 2026

Initially, the couple closely monitored footage from their Ring home-security cameras on their cellphones.

From The Wall Street Journal ● Aug. 10, 2026

With the war over, Garfield moved to the Appropriations Committee, which monitored the government's finances and spending.

From "Ambushed!" by Gail Jarrow

“SCE was actively monitoring the transmission lines in Eaton Canyon on Jan. 7 and none of these lines met our de-energization criteria,” Dunleavy said.

From Los Angeles Times ● Aug. 20, 2026

His health is further compromised by diabetes which needs careful monitoring.

From BBC ● Aug. 20, 2026

They also addressed the issue of cross-border haze, forest fires and river contamination, with the Thai general presenting his counterpart with air quality monitoring devices, according to a statement from the Thai military.

From Barron's ● Aug. 20, 2026

Former employees say the two couples have spent the years since Megxit monitoring one another, always making sure to counter any positive media coverage by planting their own.

From The Wall Street Journal ● Aug. 20, 2026

The CDO manager was further charged with monitoring the hundred or so individual subprime bonds inside each CDO, and replacing the bad ones, before they went bad, with better ones.

From "The Big Short" by Michael Lewis

Related Words

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