Junk mail 垃圾邮件，指那些主动送上门的、没有用的广告信件。这个词也适用于电子邮件中的垃圾邮件。
- Why does no one send me real letters anymore? All I ever receive is junk mail!
- When I checked my email this morning there were 15 items of junk mail advertising all kinds of weird things.
值得注意的是，另一个垃圾组合词是 junk food 垃圾食品，指那些不健康的快餐，比如汉堡、热狗等等。
- I really need to stop eating so much junk food. I‘m 2kg heavier than I was 2 months ago.