Synonyms and related words :
agile, alacritous, alert, apt, breakneck, brisk, cursory, dashing, decisive, diligent, dispatchful, double-quick, eagle-winged, effective, effectual, efficacious, efficient, express, fast, festinate, feverish, fleet, flying, furious, galloping, hair-trigger, hasty, headlong, hurried, hustling, immediate, instant, instantaneous, last-minute, light of heel, light-footed, lively, mercurial, nimble, nimble-footed, on the spot, passing, precipitate, prompt, punctual, quick, quick as lightning, quick as thought, rapid, ready, reckless, running, sharp, slap-bang, slapdash, smart, snap, snappy, spanking, speedy, spry, summary, superficial, swift, urgent, winged,