konk out

1. slang To fall asleep. A variant of "conk out." He was so tired after his long day at work that he konked out during the movie. The child finally konked out after crying for nearly an hour.

2. slang Of a machine, to break down or stop working. Judging by all that noise coming from her car, I'm pretty sure it's about to konk out. The blender finally konked out for good today. We'll need to go to the store to buy a new one.

3. slang To faint. The athlete konked out from heat stroke shortly after crossing the finish line.