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

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 To them, from day one, Chuck Schumer leading the way, this has all been political. Fox News, "Hannity: Democrats have turned SCOTUS process into a sham," 27 Sep. 2018 Noah was just like genuinely kind and lovable from day one. Carolyn Twersky, Seventeen, "You Have to Hear What Shannon Purser Said About Her On-Screen Kiss with Noah Centineo," 6 Sep. 2018 And it’ll be translated into 50 languages on day one. Eric Johnson, Recode, "The tech industry needs to reckon with the dark side of advertising, WordPress CEO Matt Mullenweg says," 2 Aug. 2018 This brush wastes no time, claiming to remove surface stains from the teeth starting on day one. Tanisha Pina, Allure, "Electric Toothbrushes Are One of the Best Amazon Prime Day Deals This Year," 17 July 2018 There are types of garments that have come from here, which in my mind have always been iconic and have been part of my design language since day one. Max Berlinger, WSJ, "Vince’s Patrik Ervell Explains the Eternal Appeal of NorCal Style," 5 Nov. 2018 Microsoft needs to be in a position where each new update is production quality from day one; a world where updating to the latest and greatest release is a no-brainer, a choice that can be confidently taken. Peter Bright, Ars Technica, "Microsoft’s problem isn’t how often it updates Windows—it’s how it develops it," 20 Oct. 2018 Having watched him since day one, Brian Smoller, senior director of broadcast services for K-State athletics, was excited to hear about Martini's career advancement. Deaundra Allen, kansascity, "Drink it in, K-State Nation: Former Wildcats star Martini called up to Oakland A's," 7 June 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

15 Jan 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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