An emblem, design, or motif attached to or placed in front of an inn, shop, etc., as a means of distinguishing it from others or of indicating the…

A signboard.

A board displaying a name, image, or some other inscription, used to give information or directions, identify a business, etc. Also figurative.

A signboard.

U.S. A small sign-board. to hang out (or set up) one's shingle, to begin to practise a profession.

Mining. A warning notice or sign beyond which a naked flame must not be used. Obsolete. rare.