- (intransitive, informal) to fall fast asleep; to sleep soundly
- He wasn't there, just the dog, conked out on the porch.
- Synonym: zonk out
- (intransitive, informal) to stop functioning
- The old car conked out halfway up the hill.
- (intransitive, informal) to die
- He lived to be 90, then conked out in his sleep.
to fall fast asleep
to stop functioning