1. flag; poster; large headline; (ınternet) advertisement on a web page which is usually in the form of an animated graphic. bannerbanner , n. [oe. banere, of. baniere, f. banniãƒâ¨re, bandiãƒâ¨re, fr. ll. baniera, banderia, fr. bandum banner, fr. ohg. bant band, strip of cloth; cf. bindan to bind, goth. bandwa, bandwo, a sign. see: band, n.]