give someone a knock on the head 意味

• （人）の頭を打つ
  

• knock someone's head off:    （人）をひどい目に遭わす、たたきのめすIf you don't listen to me, I will knock your head off. 私の話を聞かないなら、ひどい目に遭わせるぞ。
• give someone a knock:    （人）を強く打つ
• knock one's head against someone's:    （人）と鉢合わせする