1570s, "subtle;" 1580s, "elegant;" 1590s, "purified," past participle adjective from refine (v.).
1580s, of metals, c.1590 of manners, from re-, intensive prefix, + obsolete fine (v.) "make fine," from fine (adj.) "delicate." Cf. French raffiner, Italian raffinare, Spanish refinar. General and figurative sense is recorded from 1590s; of sugar, from 1610s. Related: Refined; refining.