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to defend against; to protect against
to prevent; to avert; to avoid
壁を作って洪水を禦ぐ計画がある。
There's a plan to build a wall to hold back floods.
風を禦ぐためにコートを着た。
I wore a coat to block the wind.
敵の攻撃を禦ぐのは簡単ではない。
Fending off enemy attacks isn't easy.