JD, a nobody, a nothing, boldface, brat, brazenface, chutzpanik, cipher, common man, dummy, elf, enfant terrible, figurehead, gamin, holy terror, hussy, imp, insignificancy, jackstraw, juvenile delinquent, lightweight, little fellow, little guy, little monkey, malapert, man of straw, mediocrity, minx, nebbish, nobody, nobody one knows, nonentity, nothing, nullity, obscurity, pip-squeak, puck, punk, punk kid, pup, puppy, runt, saucebox, scrub, shrimp, small fry, small potato, small potatoes, smart aleck, smart-ass, smarty, smarty-pants, spoiled brat, squirt, squit, swaggerer, upstart, urchin, whiffet, wise guy, wise-ass, zero, zilch