1. a poster or sign for public display, either fixed to a wall or carried during a demonstration.
verb
1. cover with placards:"they were placarding the town with posters"
Word Originlate 15th century (denoting a warrant or license): from Old French placquart, from plaquier ‘to plaster, lay flat’, from Middle Dutch placken. The current sense of the verb dates from the early 19th century.