1. One that admonishes, cautions, or reminds, especially with respect to matters of conduct.

2. A pupil who assists a teacher in routine duties.

3. a. A usually electronic device used to record, regulate, or control a process or system. b. A receiver, such as a screen or speaker, that is used to check the quality or content of an electronic transmission: followed the broadcast on the television monitor. c. Computer Science. A device that accepts video signals from a computer and displays information on a screen.

4. Computer Science. A program that observes, supervises, or controls the activities of other programs.

5. An articulated device holding a rotating nozzle with which a jet of water is regulated, used in mining and firefighting.

6. a. A heavily ironclad warship of the 19th century with a low, flat deck and one or more gun turrets. b. A modern warship designed for coastal bombardment.

7. Biology. Any of various tropical carnivorous lizards of the family Varanidae, living in the East Indies, southern Asia, Africa, Australia, and New Guinea and ranging in length from several centimeters to 3 meters (10 feet).

1. To check the quality or content of (an electronic audio or visual signal) by means of a receiver.

2. To check by means of an electronic receiver for significant content, such as military, political, or illegal activity: monitor a suspected criminal's phone conversations.

3. To keep track of systematically with a view to collecting information: monitor the bear population of a national park; monitored the political views of the people.

4. a. To test or sample on a regular or ongoing basis: monitored the city's drinking water for impurities. b. To test (air or an object's surface, for example) for radiation intensity.

5. To keep close watch over; supervise: monitor an examination.

6. To direct.