rationality

noun

ra·​tio·​nal·​i·​ty ˌra-shə-ˈna-lə-tē How to pronounce rationality (audio)
plural rationalities
Synonyms of rationalitynext
1
: the quality or state of being rational
2
: the quality or state of being agreeable to reason : reasonableness
3
: a rational opinion, belief, or practice
—usually plural

Examples of rationality in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The psychologists Daniel Kahneman and Amos Tversky won a Nobel Prize for pointing out that most of our decisions are not based on rationality. — Shayla Love, Vox, 25 Oct. 2026 Brabus The Brabus Urban E Fragment Edition isn't trying to win a rationality contest. — New Atlas, 16 Oct. 2026 In short, our research shows, magic thrives where individual rationality and spirituality meet. — Ruiqian Li, The Conversation, 15 Oct. 2026 To take the intentional stance toward a system is to accord it a degree of autonomy and rationality—to say that its design is working. — Joshua Rothman, New Yorker, 11 Sep. 2026 See All Example Sentences for rationality

Word History

First Known Use

1628, in the meaning defined at sense 1

Time Traveler
The first known use of rationality was in 1628

Phrases Containing rationality

Rhymes for rationality

See All Rhymes for rationality

Browse Nearby Words

rationalist
rationality
rationalization
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Cite this Entry

“Rationality.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/rationality. Accessed 27 Oct. 2026.

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Kids Definition

rationality

noun
ra·​tio·​nal·​i·​ty ˌrash-ə-ˈnal-ət-ē How to pronounce rationality (audio)
: the quality or state of being rational

Medical Definition

rationality

noun
ra·​tio·​nal·​i·​ty ˌrash-ə-ˈnal-ət-ē How to pronounce rationality (audio)
plural rationalities
1
: the quality or state of being rational
2
: the quality or state of being agreeable to reason

More from Merriam-Webster on rationality

Thesaurus: All synonyms and antonyms for rationality

Britannica.com: Encyclopedia article about rationality

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