day one

noun

often capitalized D&O
: the first day or very beginning of something

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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
He's been a 'Led Head' from day one and also loves bluegrass and big-band music. Nicole Briese, People.com, 4 Mar. 2025 Lawmakers have been trying to kill the holiday since day one. Kori Rumore, Chicago Tribune, 3 Mar. 2025 With Duda at the helm, Poland has been at the forefront of supporting Ukraine since day one of Russia's aggression. Gordon G. Chang, Newsweek, 3 Mar. 2025 Their stories remind us that entrepreneurship isn’t a path charted out from day one. Alexander Puutio, Forbes, 2 Mar. 2025 See All Example Sentences for day one

Word History

First Known Use

1971, in the meaning defined above

Time Traveler
The first known use of day one was in 1971

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Cite this Entry

“Day one.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/day%20one. Accessed 10 Mar. 2025.

Last Updated: - Updated example sentences
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