noun
making one's stance clear; showing one's true colors
A yojijukugo used when someone clearly declares their position, allegiance, or intention, often in a political or organizational context. The literal image is of unfurling a banner to show one's side.
選挙前に各党が旗幟鮮明にした。
Before the election, each party made its stance clear.
彼はついに旗幟鮮明にして、改革派に加わった。
He finally showed his true colors and joined the reformists.
A yojijukugo composed of 旗幟 (banner, flag) and 鮮明 (clear, vivid). The literal meaning is 'to unfurl one's banner clearly,' which metaphorically means to make one's position or allegiance unmistakably known.