1dum·my 
/ˈdʌmi/ noun
plural dum·mies /ˈdʌmi/ noun 1 [count] chiefly US, informal : a stupid person
▪ He's no dummy. [=fool] ▪ She loves you, you dummy. 2 [count] : a doll that is shaped like and is as large as a person
▪ a tailor's/dressmaker's dummy ▪ They practiced CPR on a dummy. ▪ a crash test dummy [=a life-size model of a person used in tests to see what happens to people when a car gets in an accident] 3 [count] : a copy of a finished object that is used during practice or training
▪ The bomb was just a dummy. 4 [count] : a large doll with a movable mouth that is used by a performer
▪ a ventriloquist's dummy 5 [noncount] : the set of cards in a game of bridge that are played faceup so everyone can see them 6 [count] Brit : pacifier
▪ He's no dummy. [=fool] ▪ She loves you, you dummy.
▪ a tailor's/dressmaker's dummy ▪ They practiced CPR on a dummy. ▪ a crash test dummy [=a life-size model of a person used in tests to see what happens to people when a car gets in an accident]
▪ The bomb was just a dummy.
▪ a ventriloquist's dummy
