Of or belonging to the first class in a recognized series of grades; esp. (a) (British) relating to the highest division in the results of a…

British. Of a railway carriage: not provided with seating; accommodating standing passengers only. Obsolete (historical in later use).

Of a room, railway compartment, building, etc.: in which smoking is not permitted. Also (of a day, period, etc.): during which smoking is not…

Chiefly in Russian and Chinese contexts: designating the highest class of accommodation available on a train, esp. a sleeper; first-class; (also)…

Designating a sign, symbol, etc., indicating that smoking is not permitted. Also: = non-smoking, adj. 1.