Wiktionary
vb. (context transitive English) To remove from a schedule.
Usage examples of "unschedule".
By chance my patrol was making an unscheduled stop at Sol, and we detected them by radar and followed them here just in time to destroy them.
And then that cursed Antarian captain had to make an unscheduled visit to Sol.
Philobosian smelled like an old couch, of hair oil and spilled soup, of unscheduled naps.
London, and I, mindful of earlier unscheduled destinations after racing, took myself circumspectly down the road to the nearest public telephone box.
SkyLight had always had a bad tendency to change perfectly good plans for no better reason than what seemed to be the unscheduled whims of the people at boardroom level.
I found myself making an unscheduled turn into a small public garden, where Oliver abruptly left me beside the first seat we came to and walked jerkily away.