| fast(adjective, adverb, fast, quick, rapid) |
| rapidly(adjective, adverb, quickly, speedily) |
| quickly(adverb, rapidly, speedily) |
| rapid(adjective, hot, fast, quick, speedy) |
| allegro(adjective, fast) |
| hastily(adverb, quickly, rapidly, speedily) |
| pronto(hot, quick, nimble, speedy, brisk) |
| quick(adjective, hot, fast, rapid, speedy) |
| speedily(adverb, quickly, rapidly) |
| suddenly(adjective, adverb, quickly, instantaneity) |
| swift(adjective, hot, fast, quick, rapid) |
| swiftly(adverb, quickly, rapidly, speedily) |
| posthaste(hot, quick, nimble, speedy, brisk) |
| apace(adverb, quickly, rapidly, speedily) |
| breakneck(adjective, hot, fast, quick, rapid) |
| expeditious(adjective, hot, fast, quick, nimble) |
| expeditiously(adverb, quickly, rapidly, speedily) |
| immediately(adverb, first, now, directly, quickly) |
| instant |
| promptly(adverb, first, now, directly, immediately) |