unscheduled

/ʌnˈskɛdʒuːld/
adjective
  1. Not planned or included in a schedule; happening at a time not previously arranged.
    • An unscheduled power outage caused the computers to shut down.
    • We had an unscheduled meeting when the CEO showed up unexpectedly.
    • The train made an unscheduled stop due to a medical emergency.
What does "unscheduled" mean? | whatsthatwordmean | whatsthatwordmean