day one

noun

variants often Day One

: the first day or very beginning of something

Synonyms of day one

• beginning
• start
• inception
• commencement
• alpha
• onset
• launch

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

Multiplayer is included from day one with up to four players, several biomes, creatures, craftables and core survival systems are playable at launch, and the developer roadmap targets additional biomes, systems and narrative content over a 2-to-3-year window. —Brian Mazique, Forbes.com, 15 May 2026

On day one of Schlossberg’s campaign, the Times reported, as his team went full speed ahead, the candidate opted to skip an opportunity to build energy among his staffers — in favor of taking a nap. —Kevin Dolak, HollywoodReporter, 15 May 2026

The films have Rediance on board as international sales agent from day one, a head start most short films never get. —Naman Ramachandran, Variety, 14 May 2026

The Nets’ front-office promotion came on the same day one of their personnel staffers left for a larger role elsewhere. —C.j. Holmes, New York Daily News, 14 May 2026

Word History

First Known Use

1953, in the meaning defined above

Rhymes for day one

• begun
• grandson
• gudrun
• handgun
• homespun
• outdone
• outrun
• pashtun
• redone
• rerun
• shotgun
• someone