rationality

noun

ra·​tio·​nal·​i·​ty ˌra-shə-ˈna-lə-tē 

plural rationalities

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 used in plural

Examples of rationality in a Sentence

Recent Examples on the Web

These vehicles need to predict movement patterns, navigate road infrastructure and, ironically, understand human irrationality with perfect rationality. —Alexandre De Vigan, Forbes.com, 15 May 2025

When faced with a choice between rationality and humanity, remember: Contracts expire. —Victoria Vitchenco, Forbes.com, 28 May 2025

At least in this instance, Mexican policy was a triumph of economic rationality over ideology. —Michael Lynch, Forbes.com, 24 Apr. 2025

Such a war would be motivated, in China, by a politics of identity that is largely impervious to economic rationality and other strategic considerations. —Rana Mitter, Foreign Affairs, 22 Apr. 2025

Word History

First Known Use

1628, in the meaning defined at sense 1

Phrases Containing rationality

• hyper-rationality

Rhymes for rationality

• abnormality
• cardinality
• commonality
• communality
• cordiality
• corporeality
• criminality
• criticality
• functionality
• generality
• geniality
• hospitality

Kids Definition

rationality

noun

ra·​tio·​nal·​i·​ty ˌrash-ə-ˈnal-ət-ē 

: the quality or state of being rational

Medical Definition

rationality

noun

ra·​tio·​nal·​i·​ty ˌrash-ə-ˈnal-ət-ē 

plural rationalities

1

: the quality or state of being rational

2

: the quality or state of being agreeable to reason