beat (someone's) brains in(redirected from beat their brains in)
beat (someone's) brains in
To strike or assault someone violently and severely, typically on the head, such that it may cause the person severe injury or death. Primarily heard in US, South Africa. I warned her that I was going to beat her brains in if she didn't stop insulting me. They left him to die after nearly beating his brains in.