Another word for junk mail or junk e-mail.
It's called "spam" because no one really likes spam (the canned meat stuff), and no one really likes junk mail.
Bob: Dang I hate spam.
Lara: Oh, I like it.
Bob: You mean that canned meat stuff?
Lara: Yeah.
Bob: Umm... I was talking about the junk mail stuff.
Lara: Ohh, right. Gotcha.