placard

noun [C]

/ˈplæk.ɑːd/

/-ɑːrd/

Definition

› a large piece of card, paper, etc. with a message written or printed on it, often carried in public places by people who are complaining about something: Demonstrators marched past holding/waving placards that said, 'Send food, not missiles'.Information and messages

(Definition of placard noun from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)