1. Stop operating or functioning
   "The engine conked out on the way to town";
   - fail, go bad, give way, die, give out, go, break, break down, pack up [Brit, informal], give up the ghost [informal]
    
2. Become exhausted or fall asleep
   "After a long day I conked out on the sofa";
   - poop out [N. Amer, informal]

Derived forms: conked out, conking out, conks out

Type of: change, fatigue, jade, pall, tire, weary