Definition:
A "nonsmoking car" is a special area in a train or sometimes a bus where people are not allowed to smoke tobacco. This means that passengers can enjoy their ride without having to breathe in smoke.
In more formal contexts, you might hear the term "nonsmoking section" used in restaurants or public places. The concept is similar, focusing on areas designated for people who do not want to be around tobacco smoke.
While "nonsmoking car" specifically refers to a transportation area, the term "nonsmoking" can apply to any space or situation where smoking is prohibited.
A "nonsmoking car" is a passenger car on a train or bus where smoking is not permitted.