unpremeditated Synonyms

accidental involuntary offhand random reflexive spontaneous unbegun unconsidered unmeant unstudied unthinking unwitting ad hoc ad lib off-the-cuff unrehearsed instinctive indeliberate inadvertent adventitious automatic casual coincidental designless extemporal extemporaneous extempore fluky fortuitous impromptu improvisatory improvised improviso impulsive unintentional