- Haphazard
- Happening by chance
- Occurring casually
- Unintentional
- Unplanned
- Happening by chance, or unexpectedly; taking place not
according to the usual course of things; casual; fortuitous; as, an
accidental visit.
- Nonessential; not necessary belonging; incidental; as,
are accidental to a play.
- Accidental
- Careless
- Not meant to happen
- Unintentional
- Unplanned
- Unplanned section in advert entries
- Unwitting
- Ad lib
- I am on time, usually first, but unprepared
- Musical compositions
- Offhand
- Spontaneously
- Spur-of-the-moment
- Unplanned, unrehearsed