To establish the truth or validity of (something) by the presentation of argument or evidence: The novel proves that the essayist can write in more than one genre. The storm proved him to be wrong in his prediction. b. To demonstrate the reality of (something): He proved his strength by doing 50 pushups. c.
We have evidence that will prove him (to be) guilty. [=that will prove that he is guilty] The tests proved the vaccine to be effective. Her second album was a hit that proved her critics wrong.