What is the meaning of conk out?

verb

• Stop operating or functioning.
  • usage: "The engine finally went"; "The car died on the road"; "The bus we travelled in broke down on the way to town"; "The coffee maker broke"; "The engine failed on the way to town"; "her eyesight went after the accident"
  • synonyms: fail, go bad, give way, die, give out, go, break, break down
• Use up all one's strength and energy and stop working.
  • usage: "At the end of the march, I pooped out"
  • synonyms: poop out, peter out, run down, run out