placard

Short definition from Wiktionary

Noun

1. 1
   A sheet of paper or cardboard with a written or printed announcement on one side for display in a public place.
2. 2
   A public proclamation; a manifesto or edict issued by authority.
3. 3
   Permission given by authority; a license.
4. 4
   An extra plate on the lower part of the breastplate or backplate of armour.
5. 5
   A kind of stomacher, often adorned with jewels, worn in the fifteenth century and later.
6. 6
   The woodwork and frame of the door of a closet etc.

Verb

1. 1
   To affix a placard to.
2. 2
   To announce with placards.