imperturbable

Merriam-Webster's Word of the Day for March 10, 2025 is: imperturbable \im-per-TER-buh-bul\ adjective Imperturbable describes someone or something marked by extreme calm; such a person or thing is very hard to disturb or upset. // The imperturbable captain did not panic when the boat sailed into the path of a violent storm. // Nothing disrupted the contestant's imperturbable focus. [See the entry >](https://www.merriam-webster.com/dictionary/imperturbable) Examples: "The thick heat is not letting up after a long stretch of nearly-90-degree-days, though the crowd has not seemed to notice. Instead, these thousands of people emanate a truly imperturbable energy as they get to see gospel legend [Mavis Staples](https://www.britannica.com/biography/Mavis-Staples) for free." — David Cohn, The Daily Californian (UC Berkeley), 13 Oct. 2024 Did you know? Imperturbable is a bit of a mouthful, but don’t let its five syllables [perturb](https://www.merriam-webster.com/dictionary/perturb) you. Instead, let us break it down: this word, as well as its antonym [perturbable](https://www.merriam-webster.com/dictionary/perturbable), comes from the Latin verb perturbare, meaning "to agitate, trouble, or throw into confusion." Perturbare comes in turn from the combination of per-, meaning "thoroughly," and turbare, meaning "to disturb"; unsurprisingly perturbare is also the source of the English verb perturb. Other perturbare descendants include [disturb](https://www.merriam-webster.com/dictionary/disturb) ("to destroy the tranquility or composure of") and [turbid](https://www.merriam-webster.com/dictionary/turbid) ("thick or opaque with or as if with roiled sediment").