1. 二手的;用过的;旧的
Second-hand things are not new and have been owned by someone else.

2. 卖旧货的
A second-hand shop sells second-hand goods.

3. (故事、观点、信息)第二手的，间接的，非亲身经历的
Second-hand stories, information, or opinions are those you learn about from other people rather than directly or from your own experience.

4. at second hand - see second