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hydration; rehydration
to hydrate; to rehydrate; to moisturize
マラソンの水分補給で水をもらった。
I got water at a hydration stop during the marathon.
熱がある時はこまめに水分補給しましょう。
When you have a fever, be sure to hydrate frequently.
暑い日の登山で、水分補給ができて本当に助かった。
On a hot day of hiking, being able to hydrate was a real lifesaver.