noun
an obnoxiously conceited and self-assertive person with pretensions to smartness or cleverness
was heckled by a smart aleck in the back row
Synonyms: know-it-all, *smartass, smarty, smarty-pants, wiseacre, wisecracker, wise guy, wisehead, wisenheimer
Related Word: blowhard, boaster, braggadocio, braggart, gasbag, windbag; exhibitionist, grandstander, show-off
Idioms: hot-air artist