| offhanded |
| snap(noun, adjective, free, casual, impulsive) |
| candid |
| haphazard(adjective, unprepared, unplanned, accidental, inadvertent) |
| hasty(adjective, thoughtless, impulsive, impetuous, unwary) |
| undevised(adjective, unprepared, unplanned, unintentional, accidental) |
| ad libitum(expression, adjective, idiom, adverb, informal) |
| automatic(adjective, simple, passionate, violent, natural) |
| improviso(adjective, free, casual, spontaneous, unprepared) |
| instinctive(noun, adjective, simple, passionate, violent) |
| rash(noun, adjective, thoughtless, impulsive, impetuous) |
| rough-and-ready(adjective, unprepared) |
| sudden(noun, adjective, thoughtless, impetuous, unwary) |
| uncontrived(adjective, simple, natural, casual, impulsive) |
| unpretentious |
| unprompted(adjective, simple, plain, violent, natural) |
| abrupt(adjective, thoughtless, impulsive, impetuous, unwary) |
| by ear(expression, adjective, idiom, free, casual) |
| extemporal(adjective, unrehearsed, extemporary) |
| extemporized(adjective, fake, informal, spontaneous, unprepared) |