1.(Yiddish) a big shot who knows it and acts that way; a boastful immoderate person
2.a person who knocks (as seeking to gain admittance);
open the door and see who the knocker is
3.one who disparages or belittles the worth of something
4.either of two soft fleshy milk-secreting glandular organs on the chest of a woman
5.a device (usually metal and ornamental) attached by a hinge to a door