a bit previous, abrupt, accident-prone, ad-lib, advanced, agile, antsy-pantsy, antsy, anxious, bearish, brash, breakneck, breathless, brief, brisk, careless, caught napping, caught off balance, caught short, chafing, choleric, combustible, contentious, cranky, cursory, dashing, desperate, devil-may-care, double-quick, eager, eagle-winged, edgy, electrifying, excited, expeditious, explosive, express, extemporaneous, extemporized, far ahead, fast, festinate, feverish, fiery, fleet, fleeting, flying, forward, fretful, fretting, furious, galloping, hair-trigger, half-baked, half-cocked, haphazard, harum-scarum, headlong, heedless, hopped-up, hot-tempered, hot, hotheaded, hurried, hustling, ill-advised, ill-considered, immediate, impatient, impetuous, impromptu, improvised, impulsive, in a lather, in a stew, in a sweat, incautious, inconsiderate, instant, instantaneous, irascible, irritable, last-minute, light-footed, light of heel, lively, mad, madcap, makeshift, mercurial, momentary, nerve-shattering, nimble-footed, nimble, not firm, on edge, on the spot, overeager, overenthusiastic, overhasty, oversoon, overzealous, passing, passionate, peppery, perfunctory, petulant, precipitant, precipitate, precipitous, precocious, premature, previous, prompt, quick-tempered, quick, quick as lightning, quick as thought, rapid, rash, reckless, restive, restless, rough-and-ready, running, rushed, rushing, shocking, short-tempered, slap-bang, slapdash, snap, snappy, spanking, speedy, splenetic, spunky, squirming, squirmy, startling, sudden, superficial, surprised, surprising, swift, taken aback, taken by surprise, taken unawares, testy, thoughtless, too early, too soon, tripped up, unanticipated, unarranged, unbegun, unconcocted, uncontrived, uncrystallized, undeliberated, undevised, uneasy, unexpected, unforeseen, unhatched, unjelled, unlooked-for, unmade, unmanufactured, unmatured, unmeditated, unorganized, unpatient, unplanned, unpredicted, unpremeditated, unprepared, unprimed, unquiet, unready, unripe, unstudied, unthinking, untimely, urgent, volatile, volcanic, wanton, waspish, wild, winged