| sudden(adjective, extraordinary, wonderful, shocking, surprise) |
| unforeseen(adjective, adverb, surprise, unexpected, surprising) |
| unanticipated(adjective, adverb, surprise, unexpected, surprising) |
| abrupt(adjective, unexpected, sudden, surprising) |
| eye-opening(adjective, amazing, shocking, surprise, astonishing) |
| all of a sudden(expression, adjective, idiom, surprising, not expected) |
| impetuous(adjective, sudden, unlooked-for, unhoped) |
| impulsive(adjective, extraordinary, wonderful, quick, shocking) |
| brusque(adjective, sudden, surprising, unlooked-for) |
| fast(adjective, sudden, surprising, unlooked-for) |
| hasty(adjective, sudden, unlooked-for, unhoped) |
| rapid(adjective, sudden, surprising, unlooked-for) |
| unexpected(adjective, adverb, surprise, surprising, unpredicted) |
| quick(adjective, sudden, surprising, unlooked-for) |
| swift(adjective, sudden, surprising, unlooked-for) |
| accelerated(adjective, sudden, unlooked-for, unhoped) |
| all at once(expression, adjective, idiom, surprising, not expected) |
| headlong(adjective, sudden, unlooked-for, unhoped) |
| hurried(adjective, sudden, unlooked-for, unhoped) |
| immediate(adjective, sudden, unlooked-for, unhoped) |