| Main Entry: | |
| Part of Speech: | adjective |
| Definition: | extremely fast |
| Synonyms: | at full tilt, dangerously fast, excessive, flat out, headlong, high-speed, lightning, precipitate, rapid, reckless, speedy, whirlwind |
| Antonyms: | extremely slow |
| Main Entry: | expeditious |
| Part of Speech: | adjective |
| Definition: | immediate, speedy |
| Synonyms: | active, alert, breakneck, brisk, diligent, effective, effectual, efficient, fast, fleet, hasty, instant, nimble, prompt, punctual, quick, rapid, ready, swift |
| Antonyms: | pokey, retarded, slow |
| Main Entry: | fast |
| Part of Speech: | adjective |
| Definition: | speedy |
| Synonyms: | PDQ, accelerated, active, agile, blue streak, breakneck, brisk, chop-chop, dashing, double-time, electric, expeditious, expeditive, flashing, fleet, fleeting, flying, hairtrigger, hasty, hot, hurried, hypersonic, in a jiffy, in nothing flat, lickety split, like a bat out of hell, like all get out, like crazy, like mad, nimble, on the double, posthaste, presto, pronto, quick, racing, rapid, ready, screamin', snap*, snappy, speedball, supersonic, swift, velocious, winged |
| Antonyms: | plodding, slow, tardy, unhurried |
| Main Entry: | fleet |
| Part of Speech: | adjective |
| Definition: | quick in movement |
| Synonyms: | agile, barreling, breakneck, brisk, expeditious, expeditive, fast, flying, hasty, in nothing flat, like greased lightning, lively, mercurial, meteoric, nimble, nimble-footed, on the double, rapid, screaming, speedball, speedy, swift, winged |
| Antonyms: | clumsy, slow |
| Main Entry: | foolhardy |
| Part of Speech: | adjective |
| Definition: | impetuous, rash |
| Synonyms: | adventuresome, adventurous, audacious, bold, breakneck, daredevil, daring, devil-may-care, harebrained, headstrong, imprudent, incautious, irresponsible, madcap, off deep end, out on limb, precipitate, reckless, temerarious, venturesome, venturous, wide open |
| Antonyms: | careful, cautious, discreet, thoughtful |
| Main Entry: | hasty |
| Part of Speech: | adjective |
| Definition: | speedy; without much thought |
| Synonyms: | PDQ, abrupt, agile, brash, breakneck, brief, brisk, careless, chop-chop, cursory, eager, expeditious, fast, fiery, fleet, fleeting, foolhardy, harefooted, headlong, heedless, hurried, ill-advised, impatient, impetuous, impulsive, incautious, inconsiderate, madcap, on the double, passing, perfunctory, precipitate, prompt, pronto, quick, quickened, quickie, rapid, rash, reckless, rushed, short, slambang, slapdash, snappy, sudden, superficial, swift, thoughtless, urgent |
| Antonyms: | delayed, lazy, lingering, loitering, slow |
| Main Entry: | headlong |
| Part of Speech: | adjective |
| Definition: | dangerous, reckless |
| Synonyms: | abrupt, brash, breakneck, daredevil, daring, foolhardy, hasty, hurried, impetuous, impulsive, inconsiderate, precipitant, precipitate, rash, rough, rushing, sudden, tempestuous, thoughtless |
| Antonyms: | careful, cautious, thoughtfully, wary |
| Main Entry: | hurried |
| Part of Speech: | adjective |
| Definition: | quick, rushed |
| Synonyms: | abrupt, breakneck, brief, cursory, fast, hasty, headlong, hectic, impetuous, perfunctory, precipitant, precipitate, precipitous, rushing, short, slapdash, speedy, subitaneous, sudden, superficial, swift |
| Antonyms: | easily, leisurely, slow, unhurried, unrushed |
| Main Entry: | posthaste |
| Part of Speech: | adjective, adverb |
| Definition: | fast |
| Synonyms: | at once, breakneck, directly, double-quick, expeditious, flat-out, fleet, fleetly, full tilt, hastily, hasty, headlong, lickety-split, pell-mell, promptly, pronto, quick, quickly, rapid, rapidly, speedily, speedy, straightaway, swift, swiftly |
| Antonyms: | eventually, slow, slowly |