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.
In the 2025-2026 offseason, baseball fans, particularly on X, lost their collective minds and any and all connection with rationality when LA added Kyle Tucker and Edwin Díaz. — Ian Miller Outkick, FOXNews.com, 21 Aug. 2026 These episodes cemented the importance of behavioral economics, revealing that human behavior often deviates from pure rationality, underscoring the need for robust financial regulation alongside monetary policy. — Hersh Shefrin, Forbes.com, 23 June 2026 American rationality is very focused on efficiency; morality doesn’t have a disproportionate importance. — Elsa Keslassy, Variety, 4 June 2026 To inject greater rationality into the system, a unified budget took effect in 1969. — Steve H. Hanke, Fortune, 14 May 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
See all Nearby Words

Cite this Entry

“Rationality.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/rationality. Accessed 1 Sep. 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

Last Updated: - Updated example sentences
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