Synonyms of rationale
1
: an explanation of controlling principles of opinion, belief, practice, or phenomena
2
: an underlying reason : basis

Did you know?

If someone asserts that the word rationale refers to a ration of ale, they are wrong, but that doesn’t mean they don’t have an actual rationale (a reason, explanation, or basis) for such a claim. “Rationale looks like the words ration and ale jammed together,” they could offer, and while that is true you’d be justified in responding: “Appearances can be deceiving.” Rationale is a direct borrowing of the Latin word rationale, with which it shares the meaning “an explanation of controlling principles of opinion, belief, practice, or phenomena.” The Latin rationale comes from a form of the adjective rationalis (“rational”), which traces back to the noun ratio, meaning “reason.” While the Latin ratio is also the forebear of the English noun ration, referring to a share of something, rationale has nothing to do with a tankard (or stein, or even a pony) of beer.

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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
And notably, the rationale for more security is a result of the court’s own decisions to enable easy access to guns. Sun Sentinel Editorial Board, Sun Sentinel, 25 July 2026 Working with reporters, Beltrán explained, was only part of his rationale. Tyler Kepner, New York Times, 24 July 2026 Trading partners from across the world have rejected the move and its rationale. Leonie Kidd, CNBC, 24 July 2026 In the months following Cal Poly’s decision to eliminate swimming, Caneer bombarded Armstrong and other university leaders with demands for records, pointed questions about the rationale behind the cuts and allegations of misconduct. Daniel Libit, Sportico.com, 23 July 2026 See All Example Sentences for rationale

Word History

Etymology

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

Browse Nearby Words

Podcast

Cite this Entry

“Rationale.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/rationale. Accessed 27 Jul. 2026.

Kids Definition

rationale

noun
: a basic reason or explanation for something

More from Merriam-Webster on rationale

Love words? Need even more definitions?

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

More from Merriam-Webster