1 (also standard class) used about ordinary accommodation in a train, etc （火车车厢等）二等: a second-class ticket 二等票a second-class compartment 二等车厢

2 (used about a university degree) of the level that is next after first-class （指大学学位）二等的，二级的: a second-class honours degree in geography 地理学二等学位

3 of little importance 不重要: Old people should not be treated as second-class citizens. 老年人不应该被视为次等公民。 ˌsecond-ˈclass adv to travel second-class 乘坐二等座位旅游to send a letter second-class 按第二类邮费投寄信件