rational

合理的な、理性的な

よく考えた判断や、納得できる理由に基づいている。

やさしい英語で： Based on careful thought and good reasons.

• That seems like a rational choice.
• We need a rational explanation for these changes.
• Her decision was rational and supported by evidence.

類義語： reasonable, logical, sensible

反対語： irrational

よく使う表現： rational decision, rational explanation, rational choice, rational argument

冷静な、理性的な

激しい感情に流されず、落ち着いてはっきり考えられる。

やさしい英語で： Able to think clearly and calmly without letting strong feelings control you.

• Try to stay rational.
• She remained rational despite the angry comments.
• Can we have a rational discussion about this?

類義語： level-headed, calm, reasonable

反対語： irrational, emotional

よく使う表現： remain rational, rational person, stay rational

正気の、理性的な

筋道立てて考え、何が起きているか理解できる。

やさしい英語で： Able to think sensibly and understand what is happening.

• He still has a rational mind.
• Her conduct was rational throughout the difficult week.
• The doctor checked whether he was rational and alert.

類義語： sane, reasonable, sensible

反対語： irrational

よく使う表現： rational mind, rational behavior, rational conduct

有理数

整数をゼロ以外の整数で割った形で表せる数。

やさしい英語で： A number that can be written as one whole number divided by another.

• One half is a rational.
• Adding two rationals gives another rational.
• Can this number be expressed as a rational?

類義語： rational number

よく使う表現： positive rational, nonzero rational, every rational