noun
plural -tors
[count] a device that is used for showing, watching, or listening to something: such as
a device that shows information or images on a screen
a device that is used to listen to sounds being made in another room
a device that shows and records information about a condition or function of the body
a student who helps the teacher at a school
a person who has the job of checking or watching some activity or behavior
verb
-tors; -tored; -toring
[+ obj] :to watch, observe, listen to, or check (something) for a special purpose over a period of time