1533, "of or pertaining to Gk. philosopher Plato" (429 B.C.E.-c.347 B.C.E.). The name is Gk. Platon, properly "broad-shouldered" (from platys "broad;" see place (n.)). His original name was Aristocles. The meaning "love (for one of the opposite sex) free of sensual desire"
(1631), which the word usually carries nowadays, is a Renaissance notion; it is based on Plato's writings in "Symposium" about the kind of interest Socrates took in young men, which originally had no reference to women.