reduce

減らす、下げる

大きさ、量、強さ、価値などを小さくしたり低くしたりすること。

やさしい英語で： To make something smaller or lower in amount, strength, or value.

• We need to reduce costs.
• The shop reduced its prices yesterday.
• Can you reduce the amount of salt?

使い方： reduce something by an amount (We reduced our spending by twenty percent.); reduce something to an amount (They reduced the price to ten pounds.)

類義語： lower, decrease, cut, lessen

反対語： increase, raise

よく使う表現： reduce costs, reduce the risk, reduce something by half, reduce speed

煮詰める

液体を煮て水分の一部を蒸発させ、濃くすること。

やさしい英語で： To boil a liquid so some water disappears and the liquid becomes thicker.

• Reduce the sauce gently.
• She reduced the wine in a small pan.
• Let the liquid reduce until it becomes thick.

使い方： reduce something by half (Reduce the stock by half before adding cream.)

類義語： boil down

よく使う表現： reduce the sauce, reduce by half, reduce over heat

還元する

物質に電子や水素を加えたり、酸素を取り除いたりして変化させること。

やさしい英語で： To change a substance by adding electrons or hydrogen, or taking away oxygen.

• Hydrogen can reduce this oxide.
• The compound was reduced in the laboratory.
• They used carbon to reduce the iron oxide.

使い方： reduce something to something (Carbon can reduce the oxide to metal.)

反対語： oxidize

よく使う表現： reduce an oxide, reduce with hydrogen, reduce to metal