quick

I (discerning) adjective acute, adept, adroit, agile, aggressive, astute, brainy, bright, brilliant, clever, deft, dexterous, discerning, educable, educatable, fiery, instructable, intelligent, irascible, irritable, keen, nimble-fingered, of ready intelligence, peppery, sagacious, schoolable, sharp, skillful, snappish, teachable, trainable II (fleeting) adjective active, artful, born, brief, caducous, cursory, deft, elusive, ephemeral, evanescent, expeditious, express, facile, fast, fleet, fleeting, frisky, hasty, hurried, immediate, impermanent, impulsive, instant, instantaneous, meteoric, momentary, nimble, passing, perfunctory, perishable, perspicacious, precipitate, proficient, prompt, rapid, ready, short-lived, speedy, spirited, sudden, summary, swift, temporary, transient, transitory, vivacious, volatile, wide-awake III index alert (agile), artful, born (alive), brief, cursory, deft, expeditious, facile, immediate (at once), impulsive (rash), instantaneous, live (conscious), perfunctory, perspicacious, precipitate, proficient, prompt, rapid, ready (prepared), summary, volatile