Vous avez cherché: wane (Anglais - Japonais)

and the night when on the wane,
退こうとする，夜に誓けて，

she is the reason your powers wane.
それが力の衰えの理由です

these places come and go as public subsidies wax and wane.
公的な補助金の増減で こういう場所は 絶えず移り変わるものだ

and glorify him in the night and when the stars begin to wane.
夜中に，また星々が退く時にも，かれを讃えなさい。

"when young amy's hope did wane... "she wandered here..."
"若いエイミーが弱った時は..."

they say it's on the wane but it's still got something hasn't it?
落ち目って言うけど、まだイケるよね。

cersei is queen mother, a title whose importance wanes with each passing day.
サーシーは王太后だ 権力は日に日に衰える