Reference meaning
day one
Last updated
The very beginning.
Other meanings
2. noun
A close, longtime friend, one who has been around since the beginning.
3. adverb
At the very beginning; when something is entirely new.
Source and scope
This definition is reproduced from English Wiktionary, sense en-day_one-en-noun-UKRd5pwV, under the CC BY-SA 4.0. It has not yet received VocabularyBase editorial review. Read the source and license details.