spontaneous - impulsive - unplanned - unintentional - uncalculated - unconsidered - unstudied - unprepared - offhand - extemporaneous - impromptu - unrehearsed - unthought-out - unarranged - uncontrived - unprompted - natural - instinctive - automatic - reflexive - involuntary - casual - haphazard - chance - accidental - random - serendipitous - fortuitous - incidental - ad-lib - on-the-spot - spur-of-the-moment - snap - off-the-cuff - fly-by-night - hit-or-miss - unorganized - unmethodical - unpremeditative - unpremeditating
Unpremeditated refers to actions or events that occur without any prior planning or forethought. Such actions are often spontaneous and can be a result of sudden impulses. While they can sometimes lead to positive and creative outcomes, they can also result in negative or unintended consequences.