Poster (7)
I believe the answer is:
placard
'poster' is the definition.
(I know that poster can be written as placard)
This is the entire clue.
(Other definitions for placard that I've seen before include "Slogan or message of protest on board" , "Make card, pal, into kind of ad" , "Sign posted in a public place as an advertisement" , "Large portable notice" , "Notice carried for public display" .)