Definition of dummy

• a. - Silent; mute; noiseless; as a dummy engine.
• a. - Fictitious or sham; feigned; as, a dummy watch.
• n. - One who is dumb.
• n. - A sham package in a shop, or one which does not contain what its exterior indicates.
• n. - 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.
• n. - One who plays a merely nominal part in any action; a sham character.
• n. - A thick-witted person; a dolt.
• n. - A locomotive with condensing engines, and, hence, without the noise of escaping steam; also, a dummy car.
• n. - The fourth or exposed hand when three persons play at a four-handed game of cards.
• n. - A floating barge connected with a pier.