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

That’s the apparent intent: to enable unaccountable, secretive policymaking with no rational basis. Basav Sen, Fortune, "Trump Thinks Propping Up Failing Coal Is a ‘National Security’ Emergency," 31 May 2018 That may not be rational — but then again, that's what Wason set out to prove, after all. Sarah Schreiber, Good Housekeeping, "This "Rational" Test Will Make You Feel Completely Irrational," 4 Nov. 2016 His photography book, The Art Of Cleanup, restores order to the most common of places with an outside-the-box approach that deconstructs the everyday and puts it back together in a rational (and humorous) way. Olivia Rassow, ELLE Decor, "Extreme Organization: A Look At "The Art of Cleanup"," 15 Nov. 2013 So, like any rational design-lover, Keltie decided to sand down the beams to remove the red stain, while opting for white walls to accentuate the height. Lucia Tonelli, ELLE Decor, "This is How TV Personality Keltie Knight Crafted the Bedroom of Her Dreams," 25 Oct. 2018 Even some of the most rational NBA front offices acted irrationally. Ben Cohen, WSJ, "The NBA’s Billion-Dollar Bear Market," 31 July 2018 And is there any reason to fear that our president will take anything but the most rational course? Eric Levitz, Daily Intelligencer, "Trump Cheers on Trade War With China As Stocks Tumble," 4 Apr. 2018 Always remember that without using rational thought, your success is entirely a matter of chance or luck. Paul C. Brunson, USA TODAY, "Paul C. Brunson: These 3 books are the best ever written on self-control and willpower," 5 July 2018 In a geopolitical climate that’s yearning for rational adults, the nostalgia for Nelson Mandela is potent. Kaitlin Menza, Town & Country, "Seeking Nelson Mandela in South Africa," 18 July 2017

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

4 Dec 2018

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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 \-​ē \ 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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More from Merriam-Webster on rational

Rhyming Dictionary: Words that rhyme with rational

Thesaurus: All synonyms and antonyms for rational

Spanish Central: Translation of rational

Nglish: Translation of rational for Spanish Speakers

Britannica English: Translation of rational for Arabic Speakers

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