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monitor Line breaks: moni|tor
Pronunciation: /ˈmɒnɪtə/

Definition of monitor in English:


1A device used for observing, checking, or keeping a continuous record of something: a heart monitor
More example sentences
  • These shortcomings underscore the appeal of so-called continuous glucose monitors, which check blood sugar levels scores of times a day.
  • A heart monitor clicked like a clock next to the bed.
  • He looked up to where the doctor was checking over the heart monitor.
detector, scanner, recorder;
security system, security camera, CCTV
1.1A person operating a monitor: a monitor aboard the vessel said he had measured radiation levels ten times the normal level
More example sentences
  • The machine monitor who has worked for the company for nearly 39 years said the news was a shock.
1.2A person who observes a process or activity to check that it is carried out fairly or correctly, especially in an official capacity: the deployment of troops went ahead despite the shooting down of an EC monitor’s helicopter the independent judicial monitor
More example sentences
  • So this time around, city officials hope election monitors will pronounce the process glitch-free.
  • Like all players in the electoral process, monitors must also abide by the rules and regulations of the game.
  • The task at hand now for international peace monitors is ensuring that the process gets back on track.
observer, watchdog, overseer, invigilator, supervisor
1.3A person who listens to and reports on foreign radio broadcasts and signals: radio monitors reported they heard the pilot say he was heading for Paris
More example sentences
  • Intelligence monitors are picking up less terror threat talk than a year ago, the Homeland Security Secretary said Thursday.
2A television receiver used in a studio to select or verify the picture being broadcast from a particular camera: the playback can be displayed on an external television screen or monitor
More example sentences
  • Products which could use the display include camera viewfinders, projectors, monitors, television sets and headsets for the military, medical and simulation markets.
  • The room has several wooden chairs with television monitors playing footage of moving clouds.
  • Now I place it under a television camera, and that is fed to a television monitor in front of Howard.
2.1A screen which displays an image generated by a computer.
Example sentences
  • If you have a mouse with a scroll wheel you can change the size of fonts and images displayed on your monitor screen with a single click.
  • Computer monitors generally have a refresh rate of at least 60 Hz, meaning the screen is refreshed at least 60 times a second.
  • Alone at his desk, the detective glances up at the black login screen displayed on the computer monitor.
2.2A loudspeaker used by performers on stage to hear themselves or in the studio to hear what has been recorded: I was amazed at the quality of the sound coming from the monitors
More example sentences
  • The musician's stage contains no wedge monitors and very few microphones.
  • The 896HD's outputs fed both the quad mix to the house and the in-ear monitors used for the stage.
  • Loud stage monitors can make the situation worse, because there's a constant slap delay when their sound bounces off of the back wall and heads back into the house.
3A school pupil with disciplinary or other special duties: he was a school monitor and a choir boy
More example sentences
  • She shook her head and leaned against him as they walked out of the school, totally unnoticed by teachers and hall monitors.
  • The approach taken by some schools to introduce pupils as monitors had proved effective at tackling vandalism on buses.
  • Since the first grade he has been always an excellent pupil and the class monitor.
senior boy, senior girl, senior pupil
4 (also monitor lizard) A large tropical Old World lizard with a long neck, narrow head, forked tongue, strong claws, and a short body. Monitors were formerly believed to give warning of crocodiles. Called goanna in Australia.
  • Family Varanidae and genus Varanus: many species. See also Komodo dragon
Example sentences
  • A good example is the savannah monitor, an African monitor lizard weighing about ten pounds, which spends most of its day patrolling its territory for tasty insects.
  • Two million years ago bizarre creatures roamed the Australian continent - the flesh-eating giant rat-kangaroo, the thunder bird, the marsupial wolf, and a giant monitor lizard.
  • Probably the most famous species of monitor lizard is the Komodo Dragon which lives on several islands in Indonesia.
5 historical A shallow-draught warship mounting one or two heavy guns for bombardment.
Example sentences
  • They were up against John Dahlgren's naval force of monitors and warships.


[with object] Back to top  
1Observe and check the progress or quality of (something) over a period of time; keep under systematic review: equipment was installed to monitor air quality
More example sentences
  • To guard against corruption, those countries will use a system of peer review to monitor deployment of funds and progress toward good governance.
  • The system monitors all workflows in progress and interprets the results upon completion of each step.
  • The duration of light and intense exercise training was also monitored during this study period.
observe, watch, keep an eye on, keep track of, track, keep under observation, keep watch on, keep under surveillance, surveil, check, keep a check on, scan, examine, study, record, note, oversee, supervise, superintend
informal keep tabs on, keep a tab on, keep a beady eye on
1.1Maintain regular surveillance over: he was a man of routine and it was easy for an enemy to monitor his movements
More example sentences
  • The door is electronically locked and monitored by both surveillance cameras and employees.
  • Architectural elements control pedestrian access, and surveillance cameras monitor people as they approach the area.
  • Thousands of police, army troops and security men stood on guard in and around the Grand Mosque as surveillance cameras monitored the crowds.
1.2Listen to and report on (a foreign radio broadcast or a telephone conversation): listening devices were used to monitor conversations it was not easy to discover exactly how many calls were monitored
More example sentences
  • Corporate spies could also use an inexpensive scanner radio to monitor the conversation.
  • Some employers will monitor telephone conversations.
  • Telephone conversations would be monitored during the gag period, it said.
1.3Check or regulate the technical quality of (a radio transmission or television signal): a sound assistant monitors the signal on headphones
More example sentences
  • To specifically monitor the fluorescence signal, we placed a bandpass filter centered at 580 nm in front of the optical detector.
  • Anania says integration was important in metro area networking because transmissions need to be monitored at each node.
  • The negative peak was observed only if the PA signal had been monitored at low, and not high, frequencies.


Early 16th century (in sense 3 of the noun): from Latin, from monit- 'warned', from the verb monere. sense 1 of the noun dates from the 1930s.

  • Today's familiar uses of monitor, for a computer or TV screen or for checking the progress or quality of something, date only from the mid 20th century. A much earlier sense was ‘a reminder or warning’, reflecting its origin in Latin monere ‘to warn’, the source also of admonish (Middle English), monster (Late Middle English), and monument (Middle English). A monitor lizard is a large tropical lizard, in Australia also called a goanna (a L19th corruption of iguana), whose name derives from the way its reactions can warn people of the presence of a venomous creature. In schools from the 16th century a monitor was a pupil with responsibility for supervising and disciplining other pupils, who in the past might have done some teaching.



Pronunciation: /mɒnɪˈtɔːrɪəl/
Example sentences
  • As the blogger put it, we become monitorial citizens, and, I'd add, better citizens.
  • This may be an answer to the changing definition of citizenship: from the early 20th century notion of the informed citizen to the ‘monitorial citizen’ of today.
  • A lot of people had been cruel to him due to his monitorial status.


Example sentences
  • I received a flood of e-mail after I wrote about the joys of dual monitorship.
  • I have come to know these men quite well during the course of this monitorship.

Words that rhyme with monitor

per capita • carpenter

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Word of the day innocuous
Pronunciation: iˈnäkyo͞oəs
not harmful or offensive