ra·​tio·​nale ˌra-shə-ˈnal How to pronounce rationale (audio)
: an explanation of controlling principles of opinion, belief, practice, or phenomena
: an underlying reason : basis

Did you know?

Rationale comes from Latin ratio, meaning "reason," and rationalis, "endowed with reason." Ratio is reasonably familiar as an English word for the relationship (in number, quantity, or degree) between things.

Examples of rationale in a Sentence

the rationale for starting the school day an hour later is that kids will supposedly get an extra hour of sleep
Recent Examples on the Web The common rationale for foreign aid to Israel is that such assistance shows that Americans are kind and benevolent. Jacob Hornberger, Orange County Register, 12 May 2024 So, any claim that something is hate speech can be converted into a rationale for censoring anything that anyone says, sooner or later. Lisa Deaderick, San Diego Union-Tribune, 12 May 2024 See all Example Sentences for rationale 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'rationale.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Latin, neuter of rationalis

First Known Use

1657, in the meaning defined at sense 1

Time Traveler
The first known use of rationale was in 1657


Dictionary Entries Near rationale

Cite this Entry

“Rationale.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/rationale. Accessed 23 May. 2024.

Kids Definition


ra·​tio·​nale ˌrash-ə-ˈnal How to pronounce rationale (audio)
: a basic reason or explanation for something

More from Merriam-Webster on rationale

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!