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.

The idea that valuing this in a rational way for tax purposes is somehow too hard is an insult to our intelligence.

From MarketWatch • Jun. 5, 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

But if AI can collate and analyze data to capture individual preferences at scale we may no longer need the assumption of the rational actor.

From The Wall Street Journal • Jun. 2, 2026

“While we do not see Meta abandoning its pursuit of AGI/ ChatGPT clones, we think this could be the first catalyst to more rational spending,” he added.

From Barron's • Jun. 2, 2026

Even the rational numbers—the set of numbers that can be written as a/b for integers a and b—were countable.

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

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