www.alphadictionary.com

Precipitated by seeing the term "book-banners" in a Wall Street Journal book review this morning. That's quite different (I think) from the more usual meaning of a waving flag or 72-point headline on a newspaper page.

The verb 'ban' of this word is part of a previous Good Word, banish, and related to banlieu, banns, and many others.

Banner as a noun is different, and related to bandolier.