rational

adjective
ra·tio·nal | \ ˈrash-nəl , ˈra-shə-nᵊl \

Definition of rational 

(Entry 1 of 2)

1a : having reason or understanding

b : relating to, based on, or agreeable to reason : reasonable a rational explanation rational behavior

2 : involving only multiplication, division, addition, and subtraction and only a finite number of times

3 : relating to, consisting of, or being one or more rational numbers a rational root of an equation

rational

noun

Definition of rational (Entry 2 of 2)

: something rational specifically : rational number

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Other words from rational

Adjective

rationally adverb
rationalness noun

Examples of rational in a Sentence

Adjective

human beings are rational creatures insisted there was a rational explanation for the strange creaking noises and that there were no such things as ghosts

Recent Examples on the Web: Adjective

Government health studies show that people who have recently eaten and are not feeling hungry are more likely to make rational decisions. Paul C. Brunson, USA TODAY, "Paul C. Brunson: These 3 books are the best ever written on self-control and willpower," 5 July 2018 And a rational way is not locking children up in detention centers or separating them from their mothers. Luke Darby, GQ, "What the Hell, Bernie Sanders?," 28 June 2018 The decision could encourage many workers perfectly happy with their unions’ work to make the economically rational decision to opt out of paying for it. Adam Liptak, New York Times, "Supreme Court Ruling Delivers a Sharp Blow to Labor Unions," 27 June 2018 Just to survive flight-or-fight situations, for example, the brain could not have evolved to develop perfectly rational decisions. Richard B. Mckenzie, WSJ, "People Aren’t Rational, and That’s Why We Need Free Trade," 15 June 2018 Confederate statues are an anathema to rational, thinking people. Lauren Ritchie, OrlandoSentinel.com, "Statue of Confederate general is no 'piece of art,' has no place in Lake County museum," 1 July 2018 Markets are a more effective mechanism for rewarding rational thinking. Richard B. Mckenzie, WSJ, "People Aren’t Rational, and That’s Why We Need Free Trade," 15 June 2018 Privacy - Terms Trouble is, fan is short for fanatic and rational doesn’t always compute. Vahe Gregorian, kansascity, "K-State's Bruce Weber now must meet expectations instead of defying them," 1 June 2018 As Canavan says, All rational thinking must begin with this world, the one that is. Nr Interview, National Review, "Capturing a Spiritual Father’s Freedom and Wisdom," 12 Jan. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'rational.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of rational

Adjective

14th century, in the meaning defined at sense 1a

Noun

1601, in the meaning defined above

History and Etymology for rational

Adjective

Middle English racional, from Anglo-French racionel, from Latin rationalis, from ration-, ratio

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Statistics for rational

Last Updated

11 Sep 2018

Look-up Popularity

Time Traveler for rational

The first known use of rational was in the 14th century

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More Definitions for rational

rational

adjective

English Language Learners Definition of rational

: based on facts or reason and not on emotions or feelings

: having the ability to reason or think about things clearly

rational

adjective
ra·tio·nal | \ ˈra-shə-nᵊl \

Kids Definition of rational

1 : having the ability to reason Humans are rational creatures.

2 : based on or showing reason rational thinking a rational decision

Other words from rational

rationally adverb

rational

adjective
ra·tio·nal | \ ˈrash-nəl, -ən-ᵊl \

Medical Definition of rational 

1a : having reason or understanding

b : relating to, based on, or agreeable to reason a rational explanation rational behavior

2 : using medical treatments based on reason or general principles used especially of an ancient school of physicians — compare empirical sense 1a

Other words from rational

rationally \ \ adverb

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rational

adjective
ra·tio·nal | \ ˈra-shə-nəl \

Legal Definition of rational 

1 : having reason or understanding

2 : relating to, based on, or guided by reason, principle, fairness, logic, a legitimate state interest, or a consideration of fact age distinctions are not subject to strict scrutiny, but they must have a rational relationship to a legitimate state interestIn re J. M., 642 A.2d 1062 (1994)

Other words from rational

rationality \ˌra-shə-ˈna-lə-tē \ noun
rationally adverb

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Comments on rational

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