1. n. something disliked, typically, but not necessarily, food. (From the brand name of a canned meat product.) I can’t eat this “spam.” It could be spoiled.
2. n. one or a series of uninvited email messages advertising money-making schemes, pornography, or sales of any kind. If I don’t recognize the sender, I assume the message is spam and I delete it.
3. tv. to clutter or fill someone’s email account with spam (sense 2). Some jerk is spamming me with an advertisement for dirty pictures.