de rigueur

Merriam-Webster's Word of the Day for March 23, 2025 is: de rigueur \duh-ree-GUR\ adjective De rigueur is a formal adjective that describes things that are necessary if you want to be fashionable, popular, socially acceptable, etc.—in other words, things required by fashion, etiquette, or custom. // Dark sunglasses are de rigueur these days among [fashionistas](https://www.merriam-webster.com/dictionary/fashionista). [See the entry >](https://bit.ly/4fOAAz9) Examples: “Summer swimwear has come a long way since itty-bitty string bikinis were de rigueur for the beach and by the pool.” — Amanda Randone, Refinery29.com, 31 May 2024 Did you know? It takes a lot of work to be cool. One needs to wear the right clothes, understand the right pop culture references, and use the right lingo before it ceases to be, ahem, [on fleek](https://bit.ly/40ylZU8). [Rigor](https://www.merriam-webster.com/dictionary/rigor) is required, is what we’re saying—a strict precision in adhering to the dictates of fashion. Such rigor is at the crux of the adjective de rigueur, a direct borrowing from French where it means “out of strictness” or “according to strict etiquette.” Rigor is also what distinguishes de rigueur from a similar French borrowing, [du jour](https://bit.ly/4affMjr). While the latter describes things that are popular, fashionable, or prominent at a particular time, as in “topic/style/buzzword du jour,” de rigueur describes that which is considered mandatory by fashion, etiquette, or custom for acceptability within a given social sphere or context. A [bucket hat](https://bit.ly/40hDMh5), for example, may be the [chapeau](https://www.merriam-webster.com/dictionary/chapeau) du jour if it is currently popular or prevalent, but it would only be de rigueur if, among a certain crowd, you would be given the side-eye for not wearing one.