unplanned

Definitions

Not anticipated or arranged in advance.

Occurring without a deliberate plan or design.

Examples

We decided to take an unplanned trip to the mountains over the weekend.

The project suffered several delays due to a series of unplanned technical issues.

Synonyms

spontaneous impromptu unpremeditated accidental haphazard extemporaneous unintended

Antonyms

planned deliberate intentional premeditated calculated organized structured