A reprieve is a break in or cancellation of a painful or otherwise lousy situation. If you're being tortured, a reprieve is a break from whatever's tormenting you.
For some, a night at the opera is a night of punishing boredom during which the only reprieve is the intermission. For others, it's baseball that feels like torture. The seventh-inning stretch is the only reprieve from a night of endless waiting. Often, you'll hear reprieve used when a court or governor decides not to execute a prisoner. That prisoner is given a reprieve and will be allowed to live. He probably won't get a reprieve from prison, though, unless he's found innocent.