Merriam-Webster's Word of the Day

Merriam-Webster's Word of the Day for March 20, 2026 is:





eureka • \yoo-REE-kuh\ • adjective

As an interjection, eureka is used to express excitement when a discovery has been made. When used as an adjective, eureka describes something (typically a moment) that is characterized by a usually sudden triumphant discovery. 

// After years of trying to piece together a concrete business idea, I had a eureka moment and everything made sense.  

See the entry > 





Examples:

“Back in 2020, Trautmann and fellow college student Max Steitz were lamenting the unrelenting loss of Louisiana wetlands, while sharing a bottle of wine. It was a eureka moment, as Trautmann and Steitz realized that by crushing wine bottles and other disposable glass into sand, they could relieve pressure on landfills and simultaneously help fend off coastal erosion.” — Doug MacCash, nola.com (New Orleans, Louisiana), 5 Dec. 2025 





Did you know?

When people exclaim “Eureka!” they are harking back to a legendary event in the life of the Greek mathematician and inventor Archimedes. While wrestling with the problem of how to determine the purity of gold, he had the sudden realization that the buoyancy of an object placed in water is equal in magnitude to the weight of the water the object displaces. According to one popular version of the legend, he made his discovery at a public bathhouse, whereupon he leapt out of his bath, exclaiming in Greek “Heurēka! Heurēka!” (“I have found it!”), and ran home naked through the streets. The absence of a contemporary source for this anecdote has done nothing to diminish its popularity over the centuries. The English word eureka, which of course hails from heurēka, has also retained its popularity; its use as an interjection dates to the early 17th century, and it gained a brand-new use in the early 20th century as an adjective describing moments of discovery or epiphany.

Merriam-Webster's Word of the Day for March 19, 2026 is:





nadir • \NAY-deer\ • noun

Nadir refers to the lowest or worst point of something. When used in astronomy, nadir describes the point of the celestial sphere that is directly opposite the zenith and vertically downward from the observer.

// Only once the novel’s protagonist reaches her nadir does she arouse the reader’s empathy, and we root for her to climb back to respectability.

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Examples:

“Sacrament dives right into the nadir of the 2020 health crisis, following a group of nurses who have moved into makeshift housing near a California hospital, to isolate from their families during the height of the case surge.” — James Folta, LitHub.com, 1 July 2025





Did you know?

Nadir is part of the galaxy of scientific words that have come to us from Arabic, a language that has made important contributions to the English lexicon especially in the fields of mathematics, astronomy, medicine, and chemistry. The source of nadir is naḍhīr, meaning “opposite”—the opposite, that is, of the zenith, the highest point of the celestial sphere which is positioned vertically above the observer. (The word zenith itself is a modification of another Arabic word that means “the way over one’s head.”) Though born of the heavens, both words are called upon to refer to earthy things too, especially a significant point or period of time, be it a high point or low one.

Merriam-Webster's Word of the Day for March 18, 2026 is:





jejune • \jih-JOON\ • adjective

Jejune is a formal word that means "uninteresting" or "boring." It is also used as a synonym of juvenile to describe things (such as behaviors, attitudes, etc.) that are immature, childish, or simplistic.

// The movie adaptation employed surreal visual effects to tell the story, making the plot, jejune in the novel, archetypal rather than artless.

// The professor made rude and jejune remarks about the students' artwork.

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Examples:

"While [author Helen] Garner has journaled most of her life, she burned her early diaries in a bonfire having deemed them too embarrassing or jejune." — The Irish Times, 29 Mar. 2025





Did you know?

Starved for excitement? You won't get it from something jejune. The term comes to us from the Latin word jejunus, which means "empty of food," "hungry," or "meager." When English speakers first used jejune back in the 1600s, they applied it in ways that mirrored the meaning of its Latin parent, lamenting "jejune appetites" and "jejune morsels." Something that is meager rarely satisfies, and before long jejune was being used not only for meager meals or hunger, but also for things lacking in intellectual or emotional substance. It's possible that the word gained its now-popular "juvenile" or "childish" sense when people confused it with the look-alike French word jeune, which means "young."

Merriam-Webster's Word of the Day for March 17, 2026 is:





Erin go bragh • \air-un-guh-BRAW\ • phrase

Erin go bragh is an Irish phrase that means “Ireland forever.”

// They proudly waved the Irish flag during the parade, shouting “Erin go bragh!”

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Examples:

“Dressed in full Irish regalia, Fitzgerald rode his horse, Jack, through the streets of Clinton every St. Patrick’s Day. Jack was also dressed for the occasion, with green ribbons on his mane and a green blanket with gold lettering, ‘Erin Go Bragh.’” — Craig S. Semon, The Worcester (Massachusetts) Telegram & Gazette, 22 Dec. 2025





Did you know?

March 17th is the feast day of the patron saint of Ireland, St. Patrick. In the United States, it is also the day of shamrocks, leprechauns, and green beer (and green everything else). Blue was once the color traditionally associated with St. Patrick, but the color green has several links to Ireland, including its use on Ireland’s flag in the form of a stripe, its symbolism of Irish nationalism and the country’s religious history, and its connection to Ireland’s nickname, The Emerald Isle. On St. Patrick’s Day, people turn to their dictionary to look up Erin go bragh, which means “Ireland forever.” The original Irish phrase was Erin go brách (or go bráth), which translates literally as “Ireland till doomsday.” It’s an expression of loyalty and devotion that first appeared in English during the late 18th-century Irish rebellion against the British.

Merriam-Webster's Word of the Day for March 16, 2026 is:





putative • \PYOO-tuh-tiv\ • adjective

Putative is a formal word used to describe something that is generally believed, supposed, or assumed to be something specified. It is always used before a noun.

// The group's putative leader was conspicuously absent from the meeting.

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Examples:

"... the painting is swept up in questions of identity, provenance, authenticity and putative value." — Manohla Dargis, The New York Times, 31 Oct. 2025





Did you know?

There's no need to make assumptions about the root behind putative—we know it comes from a form of the Latin verb putare, which means "to consider" or "to think." Putative is a rather formal word that has been part of English since the 15th century. Like apparent, presumed, and ostensible, it leaves room for a smidgen of doubt: a putative ally will very probably be there for you, and a putative successor is very likely to be the next one in charge, but life offers no guarantees in either case.