clever
able, adroit, apt, astute, brainy (informal) bright, canny, capable, cunning, deep, dexterous, discerning, expert, gifted, ingenious, intelligent, inventive, keen, knowing, knowledgeable, quick, quick-witted, rational, resourceful, sagacious, sensible, shrewd, skilful, smart, talented, witty, awkward, boring, clumsy, dense, dull, ham-fisted (informal) inept, inexpert, maladroit, slow, stupid, thick, unaccomplished, unimaginative, witless