volatile
不安定な
解説 Definition
市場、政局、感情、気質などが急に大きく振れ、予測や制御が難しい様子を表す。単なる不安定さより、少しの刺激で値動きや怒りが噴き出す危うさがある。物理的な「すぐ気化する」性質から比喩的に広がった用法。
Volatile describes something that can change suddenly and strongly, so it is hard to predict or control. It is often used for markets, politics, emotions, or a person's temper when there are sharp movements or quick explosions of feeling. Compared with a general word like unstable, volatile suggests a bigger and more dangerous swing in a short time. The word also has a physical meaning, describing a substance that easily turns into gas.
覚え方のコツ Memory Tip
volatile market は値が跳ね回る市場、volatile temper は突然怒り出す気性、と場面で覚えるとよいです。stable の反対に近いものの、ただ揺らぐだけでなく「短時間で激しく動き、次が読めない」感覚が中心です。ニュースでは政治情勢や株価、日常では感情の爆発に使われます。variable より危険な振れ幅、temporary より不穏な持続感があります。
Think of common phrases like volatile market and volatile temper. They both show the core idea: not just unstable, but moving sharply and unpredictably in a short time. It is often used in news about politics or stock prices, and in daily life for emotions that suddenly explode. Compared with variable, it feels riskier, and compared with temporary, it feels more tense and unsettling.
例文
Investors are nervous because the market has been extremely volatile this week.
今週は市場が非常に不安定なので、投資家は神経質になっている。
He is talented, but his volatile temper makes teamwork difficult.
彼は有能だが、怒りが爆発しやすい不安定な気性のせいで協力が難しい。
The country remains politically volatile after the sudden resignation of the prime minister.
首相の突然の辞任後、その国の政治情勢はなお不安定なままだ。
怒りっぽい
(意味 2)解説 Definition
人の性格や気分について、感情の起伏が激しく、急に怒ったり激しく反応したりすることを表す。議論の場面や職場で、扱いにくい人物を述べるときによく使う。常に怒っているというより、些細なきっかけで爆発しやすい不安定さを含む。
When used about a person, volatile describes someone whose feelings change quickly and who may suddenly become angry or react strongly. It is often used for a difficult personality in arguments, at work, or in tense relationships. The word suggests instability and a risk of an emotional outburst, not just a bad mood all the time.
覚え方のコツ Memory Tip
まず stable の反対に置くと覚えやすい語です。stable が「安定した」なら、volatile は「急に大きく揺れる・荒れやすい」。ニュースでは volatile market、人物には volatile temper が頻出で、価格や感情が突然跳ねる場面を思い浮かべると定着します。似た unstable も「不安定」ですが、volatile のほうが変化の激しさや爆発しそうな危うさが強め。化学では「蒸発しやすい液体」にも使うので、「市場・感情・液体がすぐ動く語」と一つにまとめると覚えやすいです。
A useful way to remember volatile is to put it next to stable. If stable means calm and steady, volatile means likely to swing, flare up, or change suddenly. Common phrases like volatile temper and volatile market can help you remember the core image: something that can move sharply or burst out without much warning. You can also link it to chemistry, where a volatile liquid easily evaporates, so the word suggests things that do not stay still for long.
例文
He has a volatile temper, so everyone tries to speak to him carefully.
彼は怒りっぽい性格なので、みんな慎重に話しかける。
The discussion became difficult because one of the managers was volatile and reacted to every small criticism.
その管理職の一人が怒りっぽく、少しの批判にも反応したので、議論は難しくなった。
She seemed calm at first, but her volatile personality made the meeting unpredictable.
最初は落ち着いて見えたが、彼女の怒りっぽい性格のせいで会議は先が読めなかった。
揮発性の
(意味 3)解説 Definition
化学で、液体や化合物が常温付近でも蒸発しやすく、気体になって空気中へ移りやすい性質をいう。volatile solvent や volatile oils のように、においが立つ・密閉が必要・吸入に注意する物質の説明で使う。
Volatile describes a substance that evaporates easily and quickly, especially in chemistry. It is often used for liquids that turn into gas at a low temperature. In other contexts, it can also mean likely to change suddenly or become dangerous, but the scientific meaning is especially common.
覚え方のコツ Memory Tip
語源の「飛ぶ」を、液体の分子が容器から空気へ飛び出すイメージに結びつけると覚えやすいです。アルコール、ガソリン、香料のように、ふたを開けるとすぐににおいが広がるものが典型です。flammable は燃えやすさ、volatile は蒸発しやすさなので、実験手順や安全表示では別の性質として読む必要があります。比喩用法の「不安定な」は、この物理的な飛びやすさから派生しています。
The root idea is “fly,” so think of a liquid that seems to fly into the air. That helps you remember why `volatile` is used for substances that evaporate easily, like a `volatile solvent`. Do not confuse it with `flammable`: one is about turning into gas easily, the other is about burning easily.
例文
The stock market has been volatile due to economic uncertainty.
株式市場は経済的な不確実性のために変わりやすい状態にある。
Her volatile temperament made it difficult for others to work with her.
彼女の気分が安定せず変わりやすい気質は、他の人が彼女と一緒に仕事をするのを難しくした。
The chemical substance is volatile and must be handled with extreme care.
その化学物質は揮発性があり、極めて注意深く取り扱う必要がある。
volatile の類義語・関連語
volatile の語源・成り立ち Etymology
volatile はラテン語 volatilis「飛びやすい」から来ており、さらに volare「飛ぶ」にさかのぼります。液体がすぐ気体になって“飛んでいく”イメージから「揮発性の」となり、関連語に volatility や volant があります。
Volatile comes from the Latin word volatilis, meaning "flying" or "able to fly," from volare, "to fly." It first described something that easily evaporates or seems to fly away, and later developed the broader sense of changing quickly and unpredictably.
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