day one

noun

variants often Day One
Synonyms of day onenext
: 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.
The pre-theater menu has been a hit since day one. Pam Kragen, San Diego Union-Tribune, 10 Feb. 2026 John Payne is out there and has been out there since day one. Andy Greene, Rolling Stone, 10 Feb. 2026 On day one hundred and eight, Powell, who married her high-school sweetheart, presented poulet en gelée à l’estragon to a friend who happened to be in the middle of a steamy office romance. Hannah Goldfield, New Yorker, 9 Feb. 2026 On day one, reigning world champion Alysa Liu made her return to the Olympics after a two-year retirement, but skated for the first time in the team event. Alice Park, Time, 9 Feb. 2026 See All Example Sentences for day one

Word History

First Known Use

1953, in the meaning defined above

Time Traveler
The first known use of day one was in 1953

Browse Nearby Words

Cite this Entry

“Day one.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/day%20one. Accessed 14 Feb. 2026.

Last Updated: - Updated example sentences
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