What is the meaning of dummy?

noun

• A person who does not talk.
  • synonyms: silent person
• An ignorant or foolish person.
  • synonyms: dumbbell, dope, boob, booby, pinhead
• A figure representing the human form.
• A cartridge containing an explosive charge but no bullet.
  • synonyms: blank, blank shell

verb

• Make a dummy of.
  • usage: "dummy up the books that are to be published"
  • synonyms: dummy up

adjective

• Having the appearance of being real but lacking capacity to function.
  • usage: "a dummy corporation"