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

Such reactions may appear irrational under one standard yet reflect a form of rationality adapted to uncertainty, vivid impressions and limited information. —Alejandro Hortal-Sánchez, The Conversation, 24 Mar. 2026

Juergen Habermas, one of the world’s most influential philosophers whose theories on communication and rationality shaped modern intellectual thought, died at 96. —Geir Moulson, Los Angeles Times, 14 Mar. 2026

Stories prey on our emotions, not our rationality, and in many cases, the former takes precedence over the latter. —Tim Brinkhof, Big Think, 3 Mar. 2026

If economic rationality alone served as the driving reason for enclosure, then privatizing wastes, land considered no good for farming, would have made no sense. —Literary Hub, 19 Feb. 2026

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