third class

third-class的词性：
n.（名词）

1. A class of mail in the U.S. postal system including all printed matter, except newspapers and magazines, that weighs less than 16 ounces and is unsealed.
第三等：美国邮政系统中邮件的一个等级，包括除报纸和杂志以外的印刷品，重量低于16盎司的不封口

2. Accommodations, as on a ship or train, of the third and usually lowest order of luxury and price.
三等房：轮船或火车上的三等房间，常是最简陋最廉价的房间

third-class的音标和读音：