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.
On day one of the tampering window, Green Bay agreed to deals with cornerback Nate Hobbs and offensive lineman Aaron Banks. Faisal Kutty, Newsweek, 11 Mar. 2025 At Google, product teams combine designers, engineers and business strategists from day one. Goran Paun, Forbes, 11 Mar. 2025 Design-first companies integrate design thinking from day one. Goran Paun, Forbes, 11 Mar. 2025 The Dolphins’ lack of movement on day one doesn’t exactly mean all hope is lost. C. Isaiah Smalls Ii, Miami Herald, 10 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

Browse Nearby Words

Cite this Entry

“Day one.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/day%20one. Accessed 22 Apr. 2025.

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!