unscheduled

British  

/ ʌnˈʃɛdjuːld /

adjective

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

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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

More than 300 TSA employees have already left the agency since the shutdown began on February 14, according to the DHS, while US media reported unscheduled absences had more than doubled.

From Barron's • Mar. 21, 2026

Trump’s announcement followed an unscheduled hourlong call with Putin about the situation in the Middle East.

From Los Angeles Times • Mar. 10, 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

Was I the only one who noticed that the bus was making an unscheduled stop?

From "The View From Saturday" by E.L. Konigsburg