unscheduled

British  

/ ʌnˈʃɛdjuːld /

adjective

1. not arranged or planned according to a programme, timetable, etc

---

Explanation

Something unscheduled is not planned for or anticipated. If your mother shows up at your door unscheduled, hope that you've been keeping the place nice and clean since you won't have time to tidy up before her arrival. The word unscheduled describes something that is not planned or scheduled in advance, as seen by the prefix un- meaning "not." An unscheduled interruption of a television program might mean there's breaking news that you need to hear. An unscheduled delay of a flight might mean you're stuck in the airport for hours. Whatever it may be, something that's unscheduled happens without your expecting it, which means it might very well throw you off your regular routine or schedule.

Example Sentences

Nearly 500 transportation security officers have quit, according to the White House, and unscheduled absences have surged since the partial shutdown began.

From Barron's • Mar. 27, 2026

And the plant itself remains unscheduled on the federal level.

From Los Angeles Times • Mar. 4, 2026

So Sauer’s claim that Murphy forced an unscheduled emergency stopover in Djibouti is just flat-out false.

From Slate • Feb. 28, 2026

When students have unscheduled free time, they typically default to the easiest option, not the most worthwhile.

From The Wall Street Journal • Feb. 24, 2026

“It was an unscheduled landing, completely unexpected. Depending on who you believe, either the radar was out of order briefly while it was landing—or it just appeared. Out of nowhere.”

From "Found" by Margaret Peterson Haddix