अर्थ : Someone who supervises (an examination).

अर्थ : Someone who gives a warning so that a mistake can be avoided.

अर्थ : An ironclad vessel built by Federal forces to do battle with the Merrimac.

अर्थ : Display produced by a device that takes signals and displays them on a television screen or a computer monitor.

अर्थ : Electronic equipment that is used to check the quality or content of electronic transmissions.

अर्थ : A piece of electronic equipment that keeps track of the operation of a system continuously and warns of trouble.

अर्थ : Any of various large tropical carnivorous lizards of Africa and Asia and Australia. Fabled to warn of crocodiles.

अर्थ : Keep tabs on. Keep an eye on. Keep under surveillance.

अर्थ : Check, track, or observe by means of a receiver.