The champion finally 'put him out of his misery' by knocking him out in the fifth round. [=the champion was beating him badly and finally ended the fight by knocking him out]
('humorous') I know you're all anxious to hear the results, so let me 'put you out of your misery'. [=let me end your suffering by telling you the results]
My former boss made my life a 'misery'. [=my former boss made my life miserable]
(..) young lady. First you gotta take the safety off. Put it back. Go ahead. Put me out of my misery. It was just a joke. If I hear any more shit about aspirins... or one more of your fucking mood swings, I'm going to tickle you to death. (..)1996 Foxfire