day one

noun, often capitalized D&O

Definition of day one

: the first day or very beginning of something

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Examples of day one in a Sentence

We've known this about the project since Day One. since day one of this project, we've always insisted that we would create the best product possible without any consideration of cost

Recent Examples on the Web

Some of these tweets are from as early as 2012—further proving that Blake has been wagging his finger since day one. Kelly O'sullivan, Country Living, "‘The Voice’ Coach Blake Shelton Has a Quirky Habit That Everyone's Talking About," 5 Mar. 2019 Evelyn, who used to appear on the TLC reality series 90 Day Fiancé, has divided folks since day one. Kayla Keegan, Good Housekeeping, "'American Idol' Fans Did NOT Like What the Judges Told Evelyn Cormier Last Night," 15 Apr. 2019 Leaving embryos undisturbed from day one to day five —when the embryo becomes what’s known as a blastocyst—rather than checking on them on day three, as many centers do, has been similarly revolutionary. Jancee Dunn, Vogue, "How California Became the World’s Fertility Treatment Destination," 13 Mar. 2019 Big shows in New York and London are titillating but can wear you out on day one. Cator Sparks, House Beautiful, "How a Designer Shops for Antiques," 19 Mar. 2019 Perhaps that’s to give it another round for people to love it from day one. Danny Murphy, Marie Claire, "Recasted: Who Would Star in a Reboot of Harold and Maude?," 12 Feb. 2019 Kim also says that Kylie has been working hard since day one and that neither Kylie nor anyone else in her family has asked for anything before starting their own projects. Tamara Fuentes, Seventeen, "Kim Kardashian Defends Kylie Jenner After Fans Attack Her Over “Self-Made” Comments," 16 July 2018 But many House members are also prepping her to hit the ground running on day one. Eslah Attar, Glamour, "Rashida Tlaib Is Determined to Change Congress," 13 Dec. 2018 And then there are give-back companies, ones that are built — from day one — with a philanthropic mission at the forefront. Jessica Chia, Allure, "4 Beauty Startups With Major Philanthropic Missions," 27 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'day one.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of day one

1971, in the meaning defined above

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Statistics for day one

Last Updated

21 May 2019

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Time Traveler for day one

The first known use of day one was in 1971

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More Definitions for day one

day one


English Language Learners Definition of day one

: the first day or very beginning of something

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