| headlong(fast, quick, summary, speedy, swift) |
| hell-for-leather(adverb, informal, fast) |
| hereupon(directly, immediately, rapidly, instantly, shortly) |
| hot(quick, rapid, nimble, speedy, brisk) |
| hypersonic(hot, quick, rapid, nimble, speedy) |
| immediate(adjective, prompt, fast, quick, summary) |
| impatient(fast, quick, rapid, speedy, swift) |
| impetuous(fast, quick, rapid, speedy, swift) |
| in a New York minute(expression, idiom, directly, immediately, rapidly) |
| in a jiff(expression, idiom) |
| in a little while(expression, idiom, soon, swiftly, snappily) |
| in a minute(expression, adverb, now, directly, immediately) |
| in a moment |
| in a second(expression, idiom, adverb, early, immediately) |
| in a short time(expression, idiom, now, soon, swiftly) |
| in a trice |
| in a twink(expression, idiom) |
| in a twinkling(expression, idiom) |
| in advance(expression, prompt, quick, timely, directly) |
| in double time(expression, idiom, soon, swiftly, snappily) |