rationality

American

[rash-uh-nal-i-tee] / ˌræʃ əˈnæl ɪ ti /

noun

plural

rationalities

the state or quality of being rational.
the possession of reason.
agreeableness to reason; reasonableness.
the exercise of reason.
a reasonable view, practice, etc.

Other Word Forms

antirationality noun
nonrationality noun

Etymology

Origin of rationality

First recorded in 1560–70, rationality is from the Late Latin word ratiōnālitās reasonableness. See rational, -ity

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

"These rules lack humanity and rationality, and they oppress us every day."

From Barron's • Jan. 9, 2026

We comfort the comfortable, and we look for hope in norms and in institutions and in rationality.

From Slate • Dec. 17, 2025

This work challenges long-held assumptions that rationality, defined as forming and updating beliefs based on evidence, belongs only to humans.

From Science Daily • Nov. 16, 2025

“Schoolteachers who bash into our heads that evolution has no rationality often completely ignore the fact that, in the long run, nature’s creations are indistinguishable from rational designs,” the neuroscientist observes.

From The Wall Street Journal • Nov. 13, 2025

It makes a lot of sense, which makes me suspect it is a call for revolution wrapped in the clothing of rationality.

From "Divergent" by Veronica Roth

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023