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