From Longman Dictionary of Contemporary Englishbe (like) banging/bashing etc your head against a brick wallbe (like) banging/bashing etc your head against a brick wallCONTINUE/NOT STOP spoken used to say that you are making no progress at all in what you are trying hard to do I’ve tried to talk some sense into them, but it’s like banging my head against a brick wall. → head
