Once synonyms such as at a time, a single time, and a while ago. Once is an adverb, and its antonyms are twice and many times.
Another word for Once
- Sometime
- Previously
- On one occasion
- One time
- Once upon a time
- Long since
- Long ago
- In the past
- In the old days
- In previous years
- In history
- In former times
- In earlier days
- In days gone by
- In bygone days
- Historically
- Formerly
- Former
- Erstwhile
- Earlier
- Before now
- Back then
- Back in the day
- A while ago
- At some point
- At one time
- At one point
- At a time
- At an earlier time
- A single time