day one

American  

noun

1. (often initial capital letters) the very first day or beginning of something.

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Etymology

Origin of day one

First recorded in 1975–80

Example Sentences

A huge component of “NCIS” that has remained consistent from day one is that it’s more than a case-of-the-week procedural.

From Los Angeles Times • Mar. 24, 2026

"We did not want this war. From day one, we have called for de-escalation," Denmark's Foreign Minister Lars Lokke Rasmussen told Danish media in Brussels before an EU foreign ministers' meeting.

From Barron's • Mar. 16, 2026

We built everything ourselves from day one, which meant by the time we were running, we understood every part of the business at a granular level.

From MarketWatch • Mar. 5, 2026

"We just thought that if she was in school from day one she'd get used to the environment better than introducing an older dog," she says.

From BBC • Mar. 4, 2026

I thought we would have a lot in common and hoped we’d have a real connection, but from day one, something was off.

From "Proud" by Ibtihaj Muhammad

Related Words

• birth
• creation
• dawn
• inauguration
• inception
• introduction
• onset
• opening
• outset
• starting point
• top