/ ˈmɒnɪtə(r); NAmE ˈmɑːn-/ noun , verb
■ noun
1.
a television screen used to show particular kinds of information; a screen that shows information from a computer :
The details of today's flights are displayed on the monitor.
a PC with a 17-inch colour monitor
—see also VDU
2.
a piece of equipment used to check or record sth :
a heart monitor
3.
a student in a school who performs special duties, such as helping the teacher
4.
a person whose job is to check that sth is done fairly and honestly, especially in a foreign country :
UN monitors declared the referendum fair.
5.
a large tropical lizard (= a type of reptile )
■ verb
1.
to watch and check sth over a period of time in order to see how it develops, so that you can make any necessary changes
SYN track :
[ vn ]
Each student's progress is closely monitored.
[also v wh- ]
2.
[ vn ] to listen to telephone calls, foreign radio broadcasts, etc. in order to find out information that might be useful
••
WORD ORIGIN
early 16th cent. (in sense 3): from Latin , from monit- warned, from the verb monere . Sense 2 dates from the 1930s.