rational

adjective
ra·​tio·​nal | \ ˈrash-nəl How to pronounce rational (audio) , 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

Keep scrolling for more

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 Fans are unlikely to be rational about Betts’s departure. Dan Shaughnessy, BostonGlobe.com, "Trading Mookie Betts means the Red Sox have given up on 2020 season," 4 Feb. 2020 An air sign, Aquarius is rational and intellectual. Sophie Saint Thomas, Allure, "The Ultimate Guide to Surviving Mercury Retrograde in 2020," 25 Jan. 2020 Medications, which mostly include antidepressants, reduce the high level of emotional arousal, allowing a person to more effectively use their rational brain in dealing with stressful conditions. Arash Javanbakht, The Conversation, "Veterans, refugees and victims of war crimes are all vulnerable to PTSD," 21 Jan. 2020 Reintroducing wolves tends to rile up emotions, pitting people against each other, and making rational wildlife management more difficult. Ben Long, Outdoor Life, "Colorado Braces for Wolves as Politics Clash with Wildlife Management," 13 Jan. 2020 Texts written by — pace Bart Ehrman — first-century Jewish peasants do not exactly tickle the modern’s hyper-rational fancies. John Hirschauer, National Review, "The Impossible Idea," 25 Dec. 2019 Erivo brings substantial humanity and complexity to Holly, but in positioning her as the imaginative Mulder to Anderson’s rational Scully, the show relies excessively on a single character to argue that monsters might actually exist. Sophie Gilbert, The Atlantic, "The Supernatural Gets Serious in The Outsider," 12 Jan. 2020 The rational and logical part of the brain, what Kahneman calls System 2, has given humans an advantage over other species. Karthik Kannan, The Conversation, "How can we make sure that algorithms are fair?," 16 Dec. 2019 His healthy lifestyle is both rational and deeply personal, driven by a family history of male heart attacks at a young age and a desire to see his children grow up. Jack Butler, National Review, "Destroying Your Lungs to Own the Libs," 7 Nov. 2019

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.

See More

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

Keep scrolling for more

Learn More about rational

Time Traveler for rational

Time Traveler

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

See more words from the same century

Statistics for rational

Last Updated

13 Feb 2020

Cite this Entry

“Rational.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/rationalness. Accessed 24 Feb. 2020.

Keep scrolling for more

More Definitions for rational

rational

adjective
How to pronounce rational (audio)

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 How to pronounce rational (audio) \

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 How to pronounce rational (audio) \

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 How to pronounce rationally (audio) \ adverb

Keep scrolling for more

rational

adjective
ra·​tio·​nal | \ ˈra-shə-nəl How to pronounce rational (audio) \

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 How to pronounce rationality (audio) \ noun
rationally adverb

Keep scrolling for more

Comments on rational

What made you want to look up rational? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

See Definitions and Examples »

Get Word of the Day daily email!

Test Your Vocabulary

More Confusing Words—Quiz

  • cats on impossible timber
  • The magician ______ moved the selected card to the top of the deck.
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Citation

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!