also: きしょく
noun
Refers to a physical flag or banner, often in formal, military, or historical contexts. The word is somewhat literary and less common in everyday speech than 旗 (はた).
軍艦は旗幟を掲げて出港した。
The warship hoisted its ensign and left port.
noun
Figurative use: one's declared standpoint or allegiance, as if raising a flag. Often appears in the set phrase 旗幟を鮮明にする (to make one's position clear).
彼は選挙戦で旗幟を鮮明にした。
He made his position clear during the election campaign.
Irregular reading marked; rarely encountered.
旗 is the common, everyday word for 'flag'. 旗幟 is more formal and literary, often used in set phrases or historical descriptions.
Compound of 旗 (flag) and 幟 (banner, flag). The reading きし is the standard on'yomi; きしょく is an irregular variant. The figurative sense derives from the idea of raising a flag to show one's allegiance.