Merriam-Webster's Word of the Day for September 18, 2025 is:

rationale • \rash-uh-NAL\  • noun

Rationale refers to an explanation or reason for something said or done. It is often used with for, behind, or of.

// City council members who oppose the zoning change should be ready to explain their rationale for voting against it.

// She's explained the rationale behind her early retirement.

See the entry >

Examples:

“There is a rationale for commercializing seagrass production, but ecologically sustainable production needs to be at the heart of that business model, and the numbers for doing that simply don't add up at the moment.” — Richard Lilley, quoted in Smithsonian Magazine, 7 Oct. 2024

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.

Merriam-Webster's Word of the Day for September 17, 2025 is:

jovial • \JOH-vee-ul\  • adjective

Jovial describes people as well as moods, attitudes, etc., that are cheerful and jolly. 

// The audience was in a jovial mood as the headlining comedian walked onto the stage.

See the entry >

Examples:

"Transport yourself to a sumptuous hidden garden somewhere in Europe, where the meats are plentiful and the specials oh so tantalizing. The rustic communal tables and jovial service will make you feel like you're hanging out with your extended family in the old country." — Briony Smith, The Toronto Star, 29 Mar. 2025

Did you know?

In ancient Roman astrology, people were thought to share the personality traits of the god whose planet was rising when they were born. The largest planet was named after the chief Roman god Jupiter, also called Jove. Jove was a sky god and a bringer of light, as well as a great protector who kept heroes focused on being loyal to the gods, the state, and family. Ancient mythology is full of stories of Jupiter (Zeus in the Greek myths) behaving badly, but jovial points only to the joy and happiness of a supremely powerful god: it describes the cheerful and jolly among us. (Jovian is the adjective that describes what is simply related to Jove/Jupiter.) Jovial has historically been contrasted with saturnine, which describes those with a gloomy or surly disposition. Sad Saturn was the father of Jupiter and his siblings, and he was exiled (understandably) for swallowing them all.

Merriam-Webster's Word of the Day for September 16, 2025 is:

debunk • \dee-BUNK\  • verb

To debunk something (such as a belief or theory) is to show that it is not true.

// The influencer remained enormously popular despite having the bulk of their health claims thoroughly debunked.

See the entry >

Examples:

“Conspiracy theorists (and those of us who argue with them have the scars to show for it) often maintain that the ones debunking the conspiracies are allied with the conspirators.” — Adam Gopnik, The New Yorker, 24 Mar. 2025

Did you know?

To debunk something is to take the bunk out of it—that bunk being nonsense. (Bunk is short for the synonymous bunkum, which has political origins.) Debunk has been in use since at least the 1920s, and it contrasts with synonyms like disprove and rebut by suggesting that something is not merely untrue but is also a sham—a trick meant to deceive. One can simply disprove a myth, but if it is debunked, the implication is that the myth was a grossly exaggerated or foolish claim.

Merriam-Webster's Word of the Day for September 15, 2025 is:

askance • \uh-SKANSS\  • adverb

Askance means "in a way that shows a lack of trust or approval" or "with a side-glance."  

// I couldn't help but look askance at the dealer's assurances that the car had never been in an accident.

// Several people eyed them askance when they walked into the room.

See the entry >

Examples:

"In other cultures they might look askance at such a gnarly, leggy thing wedged into a loaf. But we know that a whole fried soft shell crab is one of the gifts of southeast Louisiana's robust seafood heritage." — Ian McNulty, The Times-Picayune/The New Orleans Advocate Online, 1 May 2025

Did you know?

As with the similar word side-eye, writers over the years have used askance literally when someone is looking with a side-glance and figuratively when such a glance is conveying disapproval or distrust. Back in the days of Middle English you could use askaunce and a-skans and a-skaunces to mean “in such a way that,” “as if to say,” and “artificially, deceptively.” It's likely that askance developed from these forms, with some help from asqwynt meaning “obliquely, askew.” Askance was first used in the 16th century with the meaning "sideways" or "with a sideways glance.”

Merriam-Webster's Word of the Day for September 14, 2025 is:

perpetuity • \per-puh-TOO-uh-tee\  • noun

Perpetuity refers to a state of continuing forever or for a very long time.

// The property will be passed on from generation to generation in perpetuity.  

See the entry >

Examples:

“This isn't new territory for the band—beginning with 2018's Modern Meta Physic, Peel Dream Magazine have taken cues from bands like Stereolab and Pram, exploring the ways that rigid, droning repetition can make time feel rubbery. As they snap back into the present, Black sings, ‘Millions of light years, all of them ours.' The past and future fold into themselves, braided together in perpetuity.” — Dash Lewis, Pitchfork, 4 Sept. 2024

Did you know?

Perpetuity is a “forever” word—not in the sense that it relates to a lifelong relationship (as in “forever home”), but because it concerns the concept of, well, forever. Not only can perpetuity refer to infinite time, aka eternity, but it also has specific legal and financial uses, as for certain arrangements in wills and for annuities that are payable forever, or at least for the foreseeable future. The word ultimately comes from the Latin adjective perpetuus, meaning “continual” or “uninterrupted.” Perpetuus is the ancestor of several additional “forever” words, including the verb perpetuate (“to cause to last indefinitely”) and the adjective perpetual (“continuing forever,” “occurring continually”). A lesser known descendent, perpetuana, is now mostly encountered in historical works, as it refers to a type of durable wool or worsted fabric made in England only from the late 16th through the 18th centuries. Alas, nothing is truly forever.

Merriam-Webster's Word of the Day for September 13, 2025 is:

consummate • \KAHN-suh-mut\  • adjective

Someone or something described as consummate is very skilled or accomplished. Consummate can also mean “of the highest degree” and “complete in every detail.” The adjective is always used before the noun it describes.

// Ever the consummate professional, the planner ensured that no one attending the event was aware of all the elements that had not gone as planned.

See the entry >

Examples:

“... KEM's legacy serves as a blueprint for excellence. Offstage, his charm extends beyond the microphone. Friends and collaborators describe him as a consummate gentleman and leader with an infectious sense of humor.” — Raquelle Harris, Vibe, 25 July 2025

Did you know?

Consummate is a consummate example of a word that's shifted in meaning over the centuries. A 15th century addition to the language ultimately from Latin consummare, meaning “to sum up, finish,” the word first described something that has been brought to completion. Shakespeare used the word this way in Measure for Measure: “Do you the office, friar; which consummate, Return him here again.” By the early 16th century consummate had taken on the meaning of “complete in every detail.” Today it usually describes someone or something extremely skilled and accomplished, but it can also describe that which is supremely excellent, as well as that which is simply extreme.

Merriam-Webster's Word of the Day for September 12, 2025 is:

flummox • \FLUM-uks\  • verb

To flummox someone is to confuse or perplex them.

// The actor was easily flummoxed by last-minute changes to the script.

See the entry >

Examples:

“If Thursday crosswords flummox you, remember that it's much better for your stress level to do your best and sharpen your skills than to become angry because you aren't sure what's going on.” — Deb Amlen, The New York Times, 11 June 2025

Did you know?

When it comes to the origins of flummox, etymologists are, well, flummoxed. No one really knows where the word comes from. The first known print use of the verb flummox appeared in Charles Dickens' novel The Pickwick Papers in the mid-1830s, while the adjective flummoxed appeared italicized a few years earlier in a Dublin newspaper article about laborers striking against employers who oppose their rights: “Lord Cloncurry is actually flummoxed. The people refuse to work for him.” To be flummoxed by something is to be utterly confused by it—that is, to be baffled, puzzled, bewildered, completely unable to understand. Fortunately, a word can be used even if everyone is flummoxed by its etymology, and by the end of the 19th century, flummox had become quite common in both British and American English.

Merriam-Webster's Word of the Day for September 11, 2025 is:

zoomorphic • \zoh-uh-MOR-fik\  • adjective

Zoomorphic describes things that have the form of an animal.

// The local bakery is famous for its wide variety of zoomorphic treats, from “hedgehog” dinner rolls to delicate, swan-shaped pastries.

See the entry >

Examples:

“The oldest known ceramics come from a handful of sites in the Czech Republic and date back to about 28,000 B.C.E., roughly 10,000 years after the Neanderthals went extinct. A now iconic figure of a woman and assorted ceramics were found at a Czech site called Dolni Vestonice in 1925. Additional anthropomorphic and zoomorphic figurines were found over the ensuing decades, and in 2002 fingerprints were discovered on many of the objects.” — Jaimie Seaton, Smithsonian Magazine, 2 July 2024

Did you know?

The first-known use of zoomorphic in English is a translation of the French word zoomorphique, used in a mid-19th century book on paleography to describe an ornately designed Greek letter in a manuscript from the Middle Ages: “The text commences with a zoomorphic letter, formed of two winged dragons, united by the tails, the open space being ornamented with elegant arabesques, composed of leaves and flowers …” The zoo in zoomorphique comes from the Greek noun zôion, meaning “animal,” and morphique from morphē, meaning “form.” The translation of zoomorphique to zoomorphic made perfect sense given the the existence of a similarly constructed word, anthropomorphic (“having human form”), which made its debut half a century earlier.

Merriam-Webster's Word of the Day for September 10, 2025 is:

griot • \GREE-oh\  • noun

The term griot refers to any of a class of musician-entertainers of western Africa whose performances include tribal histories and genealogies. The term is also used broadly to refer to a storyteller.

// Tracing her family lineage back to West African griots inspired the singer to focus on storytelling through her music.

See the entry >

Examples:

“Music is both the subject and mechanism of Sinners, which opens with a voiceover history of how some musicians, dating back to the West African griots, have been seen as conduits between this world and the one beyond.” — Paul A. Thompson, Pitchfork, 22 Apr. 2025

Did you know?

In many West African countries, the role of cultural guardian is maintained, as it has been for centuries, by griots. Griot—a borrowing from French—refers to an oral historian, musician, storyteller, and sometimes praise singer. (Griots are called by other names as well: jeli or jali in Mande and gewel in Wolof, for example). Griots preserve the genealogies, historical narratives, and oral traditions of their tribes. Among the instruments traditionally played by griots are two lutes: the long-necked, 21-string kora, and the khalam, thought by some to be the ancestor of the banjo.

Merriam-Webster's Word of the Day for September 9, 2025 is:

insinuate • \in-SIN-yuh-wayt\  • verb

To insinuate something (especially something bad or insulting) is to say it in a subtle or indirect way. Insinuate can also mean "to gradually make (oneself) a part of a group, a person's life, etc., often by behaving in a dishonest way."

// When the teacher questioned the students about their identical test answers, they knew she was insinuating that they had cheated.

// They have managed to insinuate themselves into the city's most influential social circles.

See the entry >

Examples:

"... when perennial talk among beachgoers about where to spend those beautiful but fleeting summer days involves rumors that, perhaps Narragansett is, say, uninviting to nonlocals, officials contend that just isn't true. 'When people say that or insinuate that Narragansett Town Beach is unfriendly or unwelcoming to nonresidents, this is absolutely untruthful,' said Parks and Recreation director Michelle Kershaw." — Christopher Gavin, The Boston Globe, 3 Nov. 2024

Did you know?

Insinuating involves a kind of figurative bending or curving around your meaning: you introduce something—an idea, an accusation, a point of view—without saying it directly. The winding path is visible in the word's etymology: insinuate comes from the Latin verb sinuare, meaning "to bend or curve," which in turn comes from the Latin noun sinus, meaning "curve." The influence of Latin sinus is visible elsewhere too: in the mathematical terms sine and cosine, the adjective sinuous ("having many twists and turns"), and the noun sinus ("any of several spaces in the skull that connect with the nostrils").