Noun
1. display consisting of a device that takes signals from a computer and displays them on a CRT screen
2. someone who supervises (an examination)
3. someone who gives a warning so that a mistake can be avoided
4. electronic equipment that is used to check the quality or content of electronic transmissions
5. a piece of electronic equipment that keeps track of the operation of a system continuously and warns of trouble
6. any of various large tropical carnivorous lizards of Africa and Asia and Australia; fabled to warn of crocodiles