day one
The term "day one" can refer to both the literal first day of an event or process and a metaphorical sense of a close, longtime friend.
🇺🇸 US Voice:
🇬🇧 UK Voice:
Definition
B1General
The very first day of an event, process, or period.
Example
- She has been committed to the project since day one.
B1General
The initial stage or beginning of a particular activity or experience.
Example
- The new policy will be implemented from day one.
B2Slang
(US, informal)A close, longtime friend who has been around since the beginning.
Example
- He's been my day one, always having my back.
Similar
Terms that have similar or relatively close meanings to "day one":
one daybeginning of daythe daybig daynumber oneearly daysday of daysfirst nightfirst yeardag outday by daygood dayfirst thing