| impromptu(adjective, adverb, free, preparation, unqualified) |
| spontaneous(adjective, free, unqualified, unprepared, impromptu) |
| extemporaneous(adjective, unprepared, impromptu, unplanned, unrehearsed) |
| offhand(adjective, adverb, free, casual, preparation) |
| ad lib(expression, adjective, adverb, free, unrehearsed) |
| improvised(adjective, adverb, free, preparation, unqualified) |
| unpremeditated(adjective, free, informal, casual, impromptu) |
| unrehearsed(adjective, adverb, free, informal, preparation) |
| extempore(adjective, adverb, free, unprepared, impromptu) |
| makeshift(adjective, adverb, free, informal, casual) |
| unprepared(adjective, free, ready, unqualified, spontaneous) |
| ad-lib(adjective, adverb, manner, preparation, unqualified) |
| unplanned(adjective, free, informal, casual, unqualified) |
| spur-of-the-moment(adjective, free, informal, casual, impromptu) |
| unstudied(adjective, free, informal, casual, impromptu) |
| extemporaneously(adjective, adverb, preparation, impromptu, spontaneously) |
| extemporary(adjective, free, impromptu, improvised, extemporaneous) |
| improv(adjective, adverb, free, informal, casual) |
| informal(adjective, free, casual, snap, impromptu) |
| scratch |