1610s, literal but poetic (Donne), "having the properties of a magnet;" it is attested from 1630s in the figurative meaning "having powers of attraction" (but Donne's conceit also had that in mind), from Modern Latin magneticus, from Latin magnes (see magnet). The meaning "capable of being attracted by a magnet" is by 1837. Related: Magnetical (1580s); magnetics "the science of magnetism" (1786).
She, that should all parts to reunion bow ;
She, that had all magnetic force alone
To draw and fasten sunder'd parts in one ;
She, whom wise Nature had invented then,
When she observ'd that every sort of men
Did in their voyage, in this world's sea, stray,
And needed a new compass for their way ;
[Donne, "An Anatomy of the World"]
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.
also magnetisation, "action of magnetizing; condition of being magnetized," 1801, noun of action from magnetize.
word-forming element meaning "magnetic, magnetism," from Greek magneto-, combining form of magnes (see magnet).