Surely, reprove must mean to prove again?
You may, of course, remember that adding re- as a prefix doesn’t always mean to do again. Reprove, surprisingly, means to censure or scold. That’s right: not only is the word not what you thought, it’s actual definition is not at all what you would have expected. Then there is reproof, which is the noun form of reprove.
Used to her boss’s constant reproofs, she no longer quaked in fear when her boss would get angry.
I see both of these tricky vocabulary words all the time in the old ETS GRE Big Book. Either (or both) could very likely show up on test day. So don’t forget them, because you’d hate to have to reprove yourself after the test.