Available Definitions:
1) n. - A public proclamation; a manifesto or edict issued by authority.
2) n. - Permission given by authority; a license; as, to give a placard to do something.
3) n. - A written or printed paper, as an advertisement or a declaration, posted, or to be posted, in a public place; a poster.
4) n. - An extra plate on the lower part of the breastplate or backplate.
5) n. - A kind of stomacher, often adorned with jewels, worn in the fifteenth century and later.
6) v. t. - To post placards upon or within; as, to placard a wall, to placard the city.
7) v. t. - To announce by placards; as, to placard a sale.