| snap(adjective, free, casual, impulsive, impulse) |
| ad hoc(expression, adjective, free, casual, unplanned) |
| impulsive(adjective, adverb, simple, natural, chance) |
| off the cuff(expression, adjective, idiom, adverb, free) |
| rough-and-ready(adjective, unprepared) |
| stopgap(adjective, helping) |
| unstudied(adjective, free, simple, fake, natural) |
| ad libitum(expression, adjective, adverb, informal, unplanned) |
| haphazard(adjective, unprepared) |
| hasty(adjective, impulsive) |
| ill-considered(adjective, impulsive, unqualified, unprepared, unsuspecting) |
| improvisatory(adjective, free, casual, impulsive, impulse) |
| provisional |
| spur-of-the-moment(adjective, free, prepared, spontaneous, unprepared) |
| undevised(adjective, unprepared) |
| unscripted(adjective, spontaneous, unprepared, impromptu, unplanned) |
| abrupt(adjective, impulsive) |
| ad-libed |
| automatic(adjective, free, simple, fake, natural) |
| band-aid(adjective, crude, substitute, spontaneous, temporary) |