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

Its small domestic market inherently fosters global ambition from day one, pushing companies like Tandem Health and Legora to solve consequential problems with international scope. — Sandy Carter, Forbes.com, 27 July 2026

Six different winners from day one of the Great Britain Sail Grand Prix, yet the dominant Australians of this season never even had a sniff of the lead in Portsmouth. — Andrew Rice, New York Times, 26 July 2026

Households and local businesses can join once the system is operating, without being asked to carry the financing from day one. — Ruben Nyanguila, semafor.com, 24 July 2026

Couples who move in intentionally rather than sliding into it because a lease is up or rent is high tend to build a stronger foundation from day one. — Ashley Lynch july 23, Charlotte Observer, 23 July 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