abrupt, acute, arduous, astute, blitz, bluff, brainy, bright, clever, cliff, cute, expedite, expeditious, fast, hasty, hilly, incisive, instant, keener,
luminous, mercurial, nimble, penetrating, perspicacious, precipitous, presto, prompt, quick, quick-witted, quicker, rapid, ready, sagacious, sharp, sharp-witted, shrewd, smart, snappy, speed, speedy, spry, steep, swift, torrential, uphill, versatile, witty