From The Collaborative International Dictionary of English v.0.48 [gcide]:
Smoking \Smok"ing\,
a. & n. from Smoke.
[1913 Webster]
Smoking bean (Bot.), the long pod of the catalpa, or
Indian-bean tree, often smoked by boys as a substitute for
cigars.
Smoking car, a railway car carriage reserved for the use of
passengers who smoke tobacco.
[1913 Webster]
From WordNet (r) 3.0 (2006) [wn]:
smoking car
n 1: a passenger car for passengers who wish to smoke [syn:
smoker, smoking car, smoking carriage, {smoking
compartment}]