monitor

noun

• 1a device used for observing, checking, or keeping a continuous record of something:a heart monitor
• a person operating a monitor: a monitor aboard the vessel said he had measured radiation levels ten times the normal level
• a 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
• a 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

• 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
• a screen which displays an image generated by a computer.
• a 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

• 3a school pupil with disciplinary or other special duties: he was a school monitor and a choir boy

• 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

• 5 historical a shallow-draught warship mounting one or two heavy guns for bombardment.

verb

• observe and check the progress or quality of (something) over a period of time; keep under systematic review:equipment was installed to monitor air quality
• maintain regular surveillance over:he was a man of routine and it was easy for an enemy to monitor his movements
• listen 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
• check or regulate the technical quality of (a radio transmission or television signal): a sound assistant monitors the signal on headphones