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day one

noun

Simple Definition of day one

  • : the first day or very beginning of something

Full Definition of day one

  1. :  the first day or very beginning of something

Examples of day one

  1. We've known this about the project since Day One.

  2. <since day one of this project, we've always insisted that we would create the best product possible without any consideration of cost>



1971

First Known Use of day one

1971


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