What is the origin of exoteric?
Exoteric, the opposite of esoteric, comes from Latin exōtericus “popular (e.g., of books); not overly technical or abstruse,” a borrowing of Greek exōterikós “external, outside, popular.” The first element of the Greek word is the adverb éxō “out, out of, outside”; the last element, -ikós, is a typical adjective suffix. The middle element, -ter-, is usually called a comparative suffix, which is only one of its functions. The suffix -ter is also used in Latin and Greek to form natural or complementary pairs, e.g., Latin nōster “our” and vester “your,” and dexter “right (hand)” and sinister “left (hand).” The Latin adjectives correspond with Greek hēméteros “our” and hyméteros “your,” and dexiterós “right (hand)” and aristerós “left (hand).” Aristerós is a euphemism meaning “better (hand)” (áristos means “best” in Greek, as in aristocracy “rule of the best”). Exoteric entered English in the 17th century.