A sham package in a shop, or one which does not contain what its exterior indicates.
3.
An imitation or copy of something, to be used as a substitute; a model; a lay figure; as, a figure on which clothing is exhibited in shop windows; a blank paper copy used to show the size of the future book, etc.
4.
One who plays a merely nominal part in any action; a sham character.(Drama)
5.
An ignorant or thick-witted person; a foolish person; a dolt.
6.
A locomotive with condensing engines, and, hence, without the noise of escaping steam; also, a dummy car.(Railroad)
7.
The fourth or exposed hand when three persons play at a four-handed game of cards.(Card Playing)
8.
A floating barge connected with a pier.
Phrases & compounds
To play dummy —
to play the exposed or dummy hand in cards. The partner of the dummy plays it.