1Returning or giving back — restoring something to its original state, or passing benefits/profits back to consumers or society. Commonly used in phrases like ポイント還元 (point cashback) and 利益還元 (profit return).
このカードは買い物の5%がポイント還元される。
This card gives 5% point cashback on purchases.
企業は利益を消費者に還元すべきだ。
Companies should return their profits to consumers.
税収の一部を地域の教育に還元する方針が決まった。
A policy was decided to return part of the tax revenue to local education.
2Reduction in chemistry — a reaction in which a substance gains electrons and its oxidation state decreases. The opposite of oxidation (酸化).
鉄の酸化物を高温で還元して純粋な鉄を取り出す。
Iron oxide is reduced at high temperatures to extract pure iron.
酸化還元反応では、一方が酸化されると同時にもう一方が還元される。
In a redox reaction, one substance is oxidized while the other is simultaneously reduced.