A poster, especially for advertisement purposes, put up illegally / One who posts such posters

(idiomatic) A male exemplar of some trait.

(idiomatic) A female exemplar of some trait.

(chiefly Canada, US, idiomatic) One who is a prototypical or quintessential example of something.

(attributive, of a bed) Having four vertical columns, one in each corner, that support a tester, so that curtains can be hung to exclude draughts from the sleeper.

A four-poster bed, which has four high posts, one at each corner, supporting a canopy.

(Internet) One who top-posts.

plural of poster child

A printed public announcement that the authorities want to apprehend a person for a crime; normally, a reward is offered.

plural of poster paint