before vowels electr-, word-forming element meaning "electrical, electricity," Latinized form of Greek ēlektro-, combining form of ēlektron "amber" (see electric). As a stand-alone, formerly often short for electrotype, electroplate.
1610s, "the characteristic properties of a magnet," from Modern Latin magnetismus (see magnet + -ism). Figurative sense of "personal charm, attractive power or influence" is from 1650s; in the hypnotic sense it is from Mesmer (see mesmerism). Meaning "science of magnets and magnetic phenomena" is by early 19c.
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Definitions of electromagnetism from WordNet
magnetism produced by an electric current;
electromagnetism was discovered when it was observed that a copper wire carrying an electric current can magnetize pieces of iron or steel near it
the branch of physics concerned with electromagnetic phenomena;