poster

poster /ˈpoʊstɚ/ noun
plural posters
poster
/ˈpoʊstɚ/
noun
plural posters
Britannica Dictionary definition of POSTER
[count]
1 
a  : a usually large printed notice often having a picture on it that is put in a public place to advertise something
b  : a usually large picture that is put on walls as a decoration
2 
: a person who writes messages on an online message board