n.
 (pl. dummies)
     - a model or replica of a human being.
 - an object designed to resemble and serve as a substitute for the real one. 
▸Brit. a rubber or plastic teat for a baby to suck on.
 - (chiefly in rugby and soccer) a feigned pass or kick.
 - Bridge  the declarer's partner, whose cards are exposed on the table after the opening lead and played by the declarer. 
▸(in whist) an imaginary fourth player.
 - informal, chiefly N. Amer. a stupid person.
 
v.
 (dummies, dummying, dummied)
  - (chiefly in rugby and soccer) feign a pass or kick.
 - 
(dummy up)
 N. Amer. informal keep quiet.
 
 
  Phrase
  
    
      - sell someone a dummy
 (chiefly in rugby and soccer) deceive an opponent by feigning a pass or kick. 
    
   
  Etymology
  C16 (orig. ‘a person who cannot speak’, later ‘an imaginary fourth player in whist’): from dumb + -y1.