I. mon ‧ i ‧ tor 1 S3 W3 AC /ˈmɒnɪtə $ ˈmɑːnətər/ BrE AmE verb [transitive]
1 . to carefully watch and check a situation in order to see how it changes over a period of time:
Patients who are given the new drug will be asked to monitor their progress.
The government is monitoring the situation closely.
The temperature is carefully monitored.
monitor what/how etc
We need a better system for monitoring what is going on.
2 . to secretly listen to other people’s telephone calls, foreign radio broadcasts etc:
He suspected that his phone calls were being monitored.
II. monitor 2 BrE AmE noun [countable]
[ Date: 1500-1600 ; Language: Latin ; Origin: monere 'to warn' ]
1 . SCREEN a television or part of a computer with a screen, on which you can see pictures or information
television/TV/computer monitor
She was staring at her computer monitor.
on a monitor
We could watch what was happening on the TV monitor.
2 . PIECE OF EQUIPMENT FOR MEASURING a piece of equipment that measures and shows the level, speed, temperature etc of something:
a heart monitor
The noise monitor recorded 98 decibels.
3 . SOMEBODY WHO WATCHES AN ACTIVITY someone whose job is to watch an activity or a situation to see how it changes or develops, or to make sure that it is fair and legal:
UN monitors will remain in the country to supervise the elections.
peace/human rights etc monitors
The UN is sending peace monitors to the area.
4 . CHILD a child who has been chosen to help a teacher in some way in class
5 . SOMEBODY WHO LISTENS TO RADIO someone whose job is to listen to news or messages on a radio and report on them