Definitions

rational

[rash-uh-nl, rash-nl] / ˈræʃ ə nl, ˈræʃ nl /

ADJECTIVE

realistic; of sound mind

Synonyms

STRONGEST

analytical balanced deliberate enlightened impartial intelligent judicious levelheaded logical lucid normal prudent reasonable sane sensible sober stable thoughtful wise

STRONG

calm cool intellectual knowing objective reasoning sound synthetic thinking

WEAK

all there cerebral circumspect cognitive collected deductive discerning discriminating far-sighted perspicacious philosophic ratiocinative reflective sagacious together well-advised

Antonyms

STRONGEST

careless confused foolish idiotic illogical insane irrational nonsensical senseless stupid thoughtless unbalanced unintelligent unreasonable unstable unsystematic unwise

STRONG

agitated excited

WEAK

ridiculous unrealistic unsound

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Today I’m breaking down why I think the market’s meteoric rise is still rational, and how the software sector proves that investors are grounded in reality.

From Barron's • Jun. 8, 2026

According to China's Cyberspace Administration, the campaign's goal was to address negativity and "create a more civilised and rational online environment".

From BBC • Jun. 5, 2026

Neoclassical economic theory assumes how this rational individual behaves in response to prices and incentives, and this forms a basis to model the economy.

From The Wall Street Journal • Jun. 2, 2026

And the court continues to conduct itself as though Trump is a rational actor who will hear a no as a no.

From Slate • Jun. 1, 2026

So we can cover the infinite cohorts of rational numbers in the number line with a set of carpets, and the total size of the carpets is 2.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife

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