Dictionary.net

someone who gives a warning so that a mistake can be avoided

keep tabs on; keep an eye on; keep under surveillance

a piece of electronic equipment that keeps track of the operation of a system continuously and warns of trouble

electronic equipment that is used to check the quality or content of electronic transmissions

display consisting of a device that takes signals from a computer and displays them on a CRT screen

an iron-clad vessel built by Federal forces to do battle with the Merrimac

someone who supervises (an examination)

someone who gives a warning so that a mistake can be avoided

keep tabs on; keep an eye on; keep under surveillance

any of various large tropical carnivorous lizards of Africa Asia and Australia; fabled to warn of crocodiles

a piece of electronic equipment that keeps track of the operation of a system continuously and warns of trouble

electronic equipment that is used to check the quality or content of electronic transmissions

display consisting of a device that takes signals from a computer and displays them on a CRT screen

an iron-clad vessel built by Federal forces to do battle with the Merrimac

someone who supervises (an examination)

One who admonishes; one who warns of faults, informs of duty, or gives advice and instruction by way of reproof or caution.

Hence, specifically, a pupil selected to look to the school in the absence of the instructor, to notice the absence or faults of the scholars, or to instruct a division or class.

Any large Old World lizard of the genus Varanus; esp., the Egyptian species (V. Niloticus), which is useful because it devours the eggs and young of the crocodile. It is sometimes five or six feet long.

An ironclad war vessel, very low in the water, and having one or more heavily-armored revolving turrets, carrying heavy guns.

A tool holder, as for a lathe, shaped like a low turret, and capable of being revolved on a vertical pivot so as to bring successively the several tools in holds into proper position for cutting.

A monitor nozzle.

One who admonishes; one who warns of faults, informs of duty, or gives advice and instruction by way of reproof or caution.

Hence, specifically, a pupil selected to look to the school in the absence of the instructor, to notice the absence or faults of the scholars, or to instruct a division or class.

Any large Old World lizard of the genus Varanus; esp., the Egyptian species (V. Niloticus), which is useful because it devours the eggs and young of the crocodile. It is sometimes five or six feet long.

An ironclad war vessel, very low in the water, and having one or more heavily-armored revolving turrets, carrying heavy guns.

A tool holder, as for a lathe, shaped like a low turret, and capable of being revolved on a vertical pivot so as to bring successively the several tools in holds into proper position for cutting.

A monitor nozzle.

One who warns or advises; a senior pupil who oversees the younger ones; an ironclad warship, having low sides and one or more turrets mounted with guns.

One who admonishes: an adviser: an instructor: a pupil who assists a schoolmaster:-fem. MONITRESS.

MONITORSHIP.

An adviser; instructor.

An adviser; a pupil in temporary charge of a class.

A turreted inronclad with low, flat deck.

One who warns of faults or gives instruction in regard to duty; an older boy in a school who assists the master-the girl who does so is called a monitress, one of a family of lizards; an iron steam-vessel of war of peculiar construction.

n. [Latin] One who admonishes; -one who points out faults, or gives useful hints as to conduct or duty; a faithful counsellor; -specifically, an older scholar commissioned by the master to keep up the discipline of the class in his absence, to call the roll and register the faults of the scholars, and sometimes to teach a junior division.

n. An iron-clad war -vessel, with one or more turrets.