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

Lyra’s quest to understand Dust brings her into confrontation with human and other worldly forces who champion moral absolutism over imagination, ignorance over knowledge, authoritarianism over free will and cold, disinterested rationality over empathy. —Literary Hub, 17 Oct. 2025

The rationality police is back, Tennessee Titans fans. —Nick Suss, Nashville Tennessean, 13 Oct. 2025

Respect is built on rationality, integrity and humility. —Kate Plummer, MSNBC Newsweek, 7 Oct. 2025

Whereas Carita’s personality is charged with emotion, her daughter, Christa, depends on logic and rationality. —Christopher Vourlias, Variety, 27 Sep. 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