dummy:
(plural – dummies; pronunciation: the letter ‘u’ rhymes with the letter ‘u’ in the word “but”)

a dummy/ stupid
a person who seems (pretends) to be acting for himself in a business deal or a dispute settlement, but is really acting for another (in such situations a ‘dummy’ is usually used in order to hide the identity of the real person);
(especially in American English) a stupid person;
a silent person — a person who habitually does not move or talk freely with others;
(an insulting word, not to be used in formal situations) a person who cannot speak,

a dummy, keeping silent & aloof
Though Jonny is the real owner of the bar, his brother-in-law runs the business on his own, making Jonny sit like a dummy.
In some political systems, the head of the state, such as the president, is a dummy, just a ceremonial figure, with no powers or important responsibilities.
Susan is becoming more and more like a dummy, being sullen and keeping herself aloof — not joining her friends, not talking to anybody at home or school and not even watching TV with others.
Members of our party are all mere dummies… all the important decisions are made by the one and the only person the party chief whose word is a commandment.
(a) a plastic or wooden model of a person which is used for displaying new clothes in the shop windows (also called ‘mannequin’). For an advertisement that shows different types of tailors dummies, please click here.
(b) a stuffed figure used in shooting target practice and as punch bags for boxers. For an advertisement that shows different types of boxers’ wooden dummies, please click here.
(c) a nipple-shaped rubber or plastic device that is given to crying babies to pacify them also called a ‘pacifier’. For an article on the health issue of using a dummy, please click here & for an item of news which warns the public not use a kind of baby dummies, please click here.
