a back number

详细解释:
过期的刊物, 过时的人

例句：

I didn't buy the magazine last month; I must try to get hold of a back number so that I can catch up on the articles I missed. 我没有购买上月的杂志。我必须设法搞到过期的杂志以便能及时补读没读过的文章。