1. To end a particular financial or accounting period. The business has already closed the books for this quarter.

2. To decide that a particular situation has ended; to conclude something; to stop considering something as an option. Mindy was our top candidate for the job, but we had to close the books on her when we learned that she had lied on her resume. I think it's time for me to close the books on this situation because I'm clearly never getting my money back.