Fashionable, a.
1. Conforming to the fashion or established mode; according with the prevailing form or style; as, a fashionable dress.
2. Established or favored by custom or use; current; prevailing at a particular time; as, the fashionable philosophy; fashionable opinions.
3. Observant of the fashion or customary mode; dressing or behaving according to the prevailing fashion; as, a fashionable man.
4. Genteel; well-bred; as, fashionable society. Time is like a fashionable host That slightly shakes his parting guest by the hand. Shak.
1 other Webster entry under this spelling
Fashionable, n.
A person who conforms to the fashions; -- used chiefly in the plural.
Shades of meaning
Fernald lists fashionable only as an antonym, under antique.
He lists it without comment; the entries above explain its neighbors.