| unanticipatedly(adverb, quickly, suddenly, unexpectedly, unawares) |
| unawares(adverb, suddenly, unexpectedly, abruptly, ignorantly) |
| unexpected(adjective, violent, fast, quick, shocking) |
| unforeseen(adjective, violent, fast, quick, shocking) |
| unheralded(adjective, unexpected) |
| unpredictable(adjective, extraordinary, wonderful, shocking, astonishing) |
| unpredictably |
| unpredicted(adjective, extraordinary, wonderful, shocking, astonishing) |
| abrupt(adjective, violent, fast, quick, sudden) |
| aback(adverb, suddenly, unexpectedly, unawares, abruptly) |
| all of a sudden(expression, idiom, adverb, quickly, unexpectedly) |
| asudden(adverb, quickly, unexpectedly, abruptly, ignorantly) |
| at once(expression, adverb, soon, swiftly, snappily) |
| breakneck(adjective, violent, fast, quick) |
| brief(adjective, violent, fast, quick) |
| brisk(adjective, sudden) |
| brusque(adjective, sudden) |
| chop chop(expression, soon, swiftly, snappily, posthaste) |
| dash |
| double-quick(adverb, quick, rapidly, soon, swiftly) |