帜 is a bound form (b.f.) meaning 'flag' or 'banner', found mainly in formal or literary compounds such as 旗帜 ('flag, banner'), 独树一帜 ('to fly one's own colors, to be unique'), and 旗帜鲜明 ('to take a clear stand'). It does not stand alone as an independent word in modern Chinese; you'll always see it as part of a two-character or four-character expression.