Webster's 1828 Dictionary
ELECTRO-MAGNETIC
a.Designating what pertains to magnetism, as connected with electricity, or affected by it. Electromagnetic phenomena.
ELECTRO-MAGNETISM
n.That science which treats of the agency of electricity and galvanism in communicating magnetic properties.
Webster's 1913 Dictionary
ELECTRO-MAGNET
ELECTRO-MAGNET E *lec `tro-mag "net, n.
Defn: A mass, usually of soft iron, but sometimes of some other magnetic metal, as nickel or cobalt, rendered temporarily magnetic by being placed within a coil of wire through which a current of electricity is passing. The metal is generally in the form of a bar, either straight, or bent into the shape of a horseshoe.
ELECTRO-MAGNETIC
ELECTRO-MAGNETIC E *lec `tro-mag *net "ic, a.
Defn: Of, Pertaining to, or produced by, magnetism which is developed by the passage of an electric current. Electro-magnetic engine, an engine in which the motive force is electro-magnetism. -- Electro-magnetic theory of light (Physics ), a theory of light which makes it consist in the rapid alternation of transient electric currents moving transversely to the direction of the ray.
ELECTRO-MAGNETISM
ELECTRO-MAGNETISM E *lec `tro-mag "net *ism, n.
Defn: The magnetism developed by a current of electricity; the science which treats of the development of magnetism by means of voltaic electricity, and of the properties or actions of the currents evolved.
The Wordsmith Dictionary