monitor

Concise Oxford English Dictionary © 2008 Oxford University Press:
monitor/ˈmɒnɪtə(r)/

▶noun

• 1 a person or device that monitors something.

• 2 a television receiver used in a studio to view the picture being transmitted from a particular camera.

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

  ■ a loudspeaker used by performers on stage to hear themselves or in a studio to hear what has been recorded.

• 3 a school pupil with disciplinary or other special duties.

• 4 (also monitor lizard) a large tropical lizard with a long neck and a short body, formerly believed to give warning of crocodiles. [Genus Varanus: many species.]

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

▶verb observe and check over a period of time.

■ maintain regular surveillance over.

■ listen to and report on (a radio broadcast or telephone conversation).

– derivatives
monitorial adjective,
monitorship noun.

– origin C16: from L., from monit-, monere ‘warn’.