placard
UK: ˈplækɑːd | US: ˈplækɑːrd
n. a large printed notice, picture, or sign displayed in a public place
vt. to post or display notices publicly
The word "placard" originated in late Middle English, borrowed from Old French placard (official document or notice). It evolved from the idea of a flat surface (plac) used for posting notices, combined with the suffix -ard to form a noun. Over time, it shifted from referring to official documents to any large public notice or sign.
Protesters carried a placard demanding climate action.
The museum displayed a placard explaining the artwork.
She placarded the neighborhood with flyers about the lost dog.
The placard on the door announced the store’s closure.
Volunteers held placards during the rally to support the cause.