Spike是“尖刺”，head on a spike是什么意思呢？请看对话：

    A: What’s up? Calm down and talk to me.

    B: Can you believe it? My boyfriend cheated on me. And I caught him kissing my friend Lindsay!

    A: Just break up with him. You deserve much better than him.

    B: I will. But before that, I want his head on a spike!

    Note: If someone wants a head on a spike, they want to destroy or really punish a person. “Head on a spike” is probably inspired by people who waged primitive wars in early human history. Back then, people sometimes cut off the head of an enemy soldier and put it on a spike — a long sharp nail such as the top of a spear — and displayed it as a trophy.