knocker (
http://definr.com/knocker)
n 1: a person who knocks (as seeking to gain admittance); "open
the door and see who the knocker is"
2: one who disparages or belittles the worth of something [syn:
detractor,
disparager,
depreciator]
3: either of two soft fleshy milk-secreting glandular organs on
the chest of a woman [syn:
breast,
bosom,
boob,
tit,
titty]
4: a device (usually metal and ornamental) attached by a hinge
to a door [syn:
doorknocker]