Other forms: banners
A banner is a long strip of cloth with words or a design on it, held up where people can read it. Two marchers carrying one between poles at the front of a crowd; a HAPPY BIRTHDAY banner taped across the kitchen wall.
Online, the banner is the wide advertisement across the top of a page — banner ads, and the banner blindness that makes readers skip past them without seeing them. A newspaper's banner headline runs the full width of the front page. 'Under the banner of' means acting in the name of something: a march under the banner of free speech. In medieval war and in fantasy, a lord's banner is the flag his men follow, which is where bannermen and banner-bearer come from. American English adds 'a banner year', meaning an outstandingly good one.
Shares are an estimate: a language model read 19 sentences found in the wild and placed 11 of them on a sense (8 were unclear) — a count of our sample, not a measurement of English.
Middle English baner came from Old French baniere, and behind that stands a Germanic word from the same root as band. The banner was the cloth that showed which band of men you belonged to — a sign to gather under, centuries before it was ever an advertisement.
Middle English
baner
English, today
banner
From Middle English baner. From Middle English baner, from Old French baniere (Modern bannière), of gem - origin. More at band.
Etymology from Wiktionary, CC BY-SA