Synonyms of unpremeditated

2 Syllables

unmeant, adlib, random, driftless, headlong, will-less, casual, re-flex, unthought, improv, hasty, offhand

3 Syllables

instinctual, objectless, unscripted, unaimed, impromptu, haphazard, unthinking, impetuous, unguarded, hot-and-cold, unprompted, hit-or-miss, off-the-cuff

4 Syllables

improviso, unintended, intuitional, impulsive, inadvertent, extempore, undesigned, instinctive, reflexive, accidental, uncircumspect

5 Syllables

spur-of-the-moment, second-nature, extemporaneous, unintentional, uncalculated, irreflective, involuntary, unmeditated, extemporary

6 Syllables

undeliberate, improvisatory