| snapper(adjective, off-the-cuff, on-the-spot, unmeditated, autoschediastic) |
| spontaneously(adverb, impromptu, improv, extemporaneously) |
| spur-of-the-moment(adjective, informal, impulsive, snap, unrehearsed) |
| subitaneous(adjective, violent, fast, quick) |
| surprised(adjective, vulnerable, unaware) |
| swift(adjective, violent, fast, quick) |
| taken off guard(expression, adjective, idiom, vulnerable, unaware) |
| taking for ride(expression, adjective, idiom, informal, snap) |
| thought out loud(expression, adjective, idiom, informal, snap) |
| thoughtless(adjective, foolish, unwise) |
| throwaway |
| tossed off(expression, adjective, informal, snap, impromptu) |
| tossed out(expression, adjective, informal, snap, unrehearsed) |
| unanticipated(adjective, violent, fast, quick, subitaneous) |
| unaware(adjective, vulnerable) |
| unexpected(adjective, violent, fast, quick) |
| unforeseen(adjective, violent, fast, quick) |
| unhandy |
| unpracticed |
| unpremeditated(adjective, informal, snap, unrehearsed) |