Meaning of “dummy” - Learner’s Dictionary

dummy

noun [ C ] uk us /ˈdʌmi/
BABY EQUIPMENT UK (US pacifier)

a small, rubber object that a baby sucks to stop it crying

STUPID PERSON mainly US informal

a stupid person:

She's no dummy.
MODEL

a model of a person

(Definition of “dummy noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)