Featured Snippet Answer
The closest synonym for once is formerly. Both words describe something that was true or happened at an earlier time but is no longer the case. “Once” is more common in everyday speech, while “formerly” sounds slightly more formal.Have you ever told a story that started with “Once, I lived in a tiny apartment…”? That small word “once” is doing a big job it’s telling your listener something happened in the past but not anymore.
Once means at an earlier time, or formerly. It’s a simple word, but writers often use it over and over in the same paragraph, which can feel repetitive.
Learning synonyms for once gives your writing more variety and a more polished feel. Whether you’re telling a story, writing an essay, or just chatting, swapping out once for a fitting alternative can make your sentences sound fresher.
This guide breaks down accurate synonyms for once, along with meanings, examples, and answers to common questions.
Synonyms for Once
| # | Synonym | Relationship | Direct Replacement | Difficulty | Best Used For |
| 1 | Formerly | Exact synonym | Yes | Intermediate | Formal writing, business writing |
| 2 | Previously | Exact synonym | Yes | Intermediate | Formal writing, academic writing |
| 3 | At one time | Near synonym | Yes | Beginner | Daily conversation |
| 4 | In the past | Near synonym | Yes | Beginner | Daily conversation, essays |
| 5 | At some point | Contextual alternative | Sometimes | Beginner | Daily conversation |
| 6 | Before | Near synonym | Sometimes | Beginner | Daily conversation |
| 7 | Back then | Contextual alternative | Yes | Beginner | Informal conversation |
| 8 | At a former time | Near synonym | Yes | Intermediate | Formal writing |
| 9 | Sometime ago | Contextual alternative | Sometimes | Beginner | Daily conversation |
| 10 | Erstwhile | Near synonym | Sometimes | Advanced | Literature, creative writing |
| 11 | Of yore | Related term | No | Advanced | Literature, poetic writing |
| 12 | In days gone by | Related term | No | Intermediate | Creative writing, storytelling |
| 13 | In olden days | Related term | No | Beginner | Storytelling, creative writing |
Table of Contents
- Formerly
- Previously
- At one time
- In the past
- At some point
- Before
- Back then
- At a former time
- Sometime ago
- Erstwhile
- Of yore
- In days gone by
- In olden days
Quick Facts About Once
- Focus keyword: once
- Part of speech: adverb (also used as a conjunction, meaning “as soon as”)
- Simple pronunciation: WUHNS
- IPA pronunciation: /wʌns/
- Number of syllables: 1
- Word origin: From Old English ānes, related to the word “one.” It originally meant “one time” and later developed the meaning “at a former time.”
- Other word forms: none (once does not change form)
- Formality level: Neutral
- Difficulty level: Beginner
- CEFR level: A2
Meaning and Usage of Once
Once means at an earlier time, or formerly. It shows that something was true or happened before, but it isn’t true or happening now.
It’s commonly used in stories, personal history, and descriptions of change. You’ll often see it at the start of a sentence, like in fairy tales, or in the middle of a sentence describing something from the past.
Example 1: This quiet neighborhood was once a busy farming village.
Example 2: She once worked as a nurse before she became a teacher.
Detailed Synonym Sections
1. Formerly: A Synonym for Once
Relationship: Exact synonym
Direct Replacement: Yes
Difficulty Level: Intermediate
Meaning: Formerly means at an earlier time, before now.
Difference: “Formerly” sounds slightly more formal and precise than “once,” making it a better fit for official or professional writing.
Best Used For: Formal writing, business writing
Examples:
- The building was formerly a public library before it became a museum.
- He is formerly the manager of the downtown branch.
2. Previously: A Synonym for Once
Relationship: Exact synonym
Direct Replacement: Yes
Difficulty Level: Intermediate
Meaning: Previously means at a time before now, or before something else happened.
Difference: “Previously” often connects two events in a clear time order, while “once” can stand alone without pointing to a second event.
Best Used For: Formal writing, academic writing
Examples:
- She had previously lived in three different countries before settling down.
- The company previously operated under a different name.
3. At one time: A Synonym for Once
Relationship: Near synonym
Direct Replacement: Yes
Difficulty Level: Beginner
Meaning: At one time means during a period in the past.
Difference: “At one time” is a phrase rather than a single word, and it often adds a slightly stronger sense of change than “once.”
Best Used For: Daily conversation
Examples:
- At one time, this street was full of small family shops.
- He was, at one time, one of the top players on the team.
4. In the past: A Synonym for Once
Relationship: Near synonym
Direct Replacement: Yes
Difficulty Level: Beginner
Meaning: In the past means during an earlier period of time.
Difference: “In the past” is broader and less specific than “once,” which usually points to a single earlier time or period.
Best Used For: Daily conversation, essays
Examples:
- In the past, people wrote letters instead of sending texts.
- She struggled with public speaking in the past, but she’s confident now.
5. At some point: A Synonym for Once
Relationship: Contextual alternative
Direct Replacement: Sometimes
Difficulty Level: Beginner
Meaning: At some point means at an unspecified time, in the past or future.
Difference: “At some point” doesn’t always mean the past, so it only works as a synonym for “once” when the context is clearly about a former time.
Best Used For: Daily conversation
Examples:
- At some point, we all lived in that old apartment building together.
- He mentioned that, at some point, he wanted to travel the world.
6. Before: A Synonym for Once
Relationship: Near synonym
Direct Replacement: Sometimes
Difficulty Level: Beginner
Meaning: Before means at an earlier time than now or than another event.
Difference: “Before” is more casual and general, while “once” often adds a light storytelling tone.
Best Used For: Daily conversation
Examples:
- I lived in a smaller town before, but I moved for work.
- He never liked coffee before, but now he drinks it every morning.
7. Back then: A Synonym for Once
Relationship: Contextual alternative
Direct Replacement: Yes
Difficulty Level: Beginner
Meaning: Back then means at that earlier time being talked about.
Difference: “Back then” is casual and conversational, while “once” fits both casual and formal writing.
Best Used For: Informal conversation
Examples:
- Back then, we didn’t even have cell phones.
- Back then, this whole area was just open fields.
8. At a former time: A Synonym for Once
Relationship: Near synonym
Direct Replacement: Yes
Difficulty Level: Intermediate
Meaning: At a former time means during an earlier period that has since ended.
Difference: “At a former time” is more formal and wordier than “once,” so it fits official or descriptive writing better than casual speech.
Best Used For: Formal writing
Examples:
- At a former time, this land belonged to a large farming family.
- The castle served, at a former time, as a royal residence.
9. Sometime ago: A Synonym for Once
Relationship: Contextual alternative
Direct Replacement: Sometimes
Difficulty Level: Beginner
Meaning: Sometime ago means at an unspecified point in the past.
Difference: “Sometime ago” focuses on the idea that time has passed, while “once” simply marks that something happened before.
Best Used For: Daily conversation
Examples:
- Sometime ago, I read a book that completely changed how I think.
- We met sometime ago at a friend’s birthday party.
10. Erstwhile: A Synonym for Once
Relationship: Near synonym
Direct Replacement: Sometimes
Difficulty Level: Advanced
Meaning: Erstwhile means former or at a previous time.
Difference: “Erstwhile” is an old-fashioned, literary word, while “once” is used naturally in everyday speech.
Best Used For: Literature, creative writing
Examples:
- Her erstwhile business partner now runs a rival company.
- The erstwhile champion returned to the ring for one final match.
11. Of yore: A Synonym for Once
Relationship: Related term
Direct Replacement: No
Difficulty Level: Advanced
Meaning: Of yore means belonging to a long time ago, often used in a poetic or nostalgic way.
Difference: “Of yore” is a fixed poetic phrase, while “once” is a plain, everyday word with no dramatic tone.
Best Used For: Literature, poetic writing
Examples:
- The old knights of yore were said to protect the village.
- Songs of yore often told stories of brave travelers.
12. In days gone by: A Synonym for Once
Relationship: Related term
Direct Replacement: No
Difficulty Level: Intermediate
Meaning: In days gone by means at a time long before now, often with a nostalgic feeling.
Difference: “In days gone by” is a longer, more emotional phrase, while “once” is short and neutral.
Best Used For: Creative writing, storytelling
Examples:
- In days gone by, families gathered around the radio for entertainment.
- In days gone by, this river was the town’s main source of water.
13. In olden days: A Synonym for Once
Relationship: Related term
Direct Replacement: No
Difficulty Level: Beginner
Meaning: In olden days means a long time ago, often used when telling stories to children.
Difference: “In olden days” is playful and storybook-like, while “once” is more common in everyday writing and speech.
Best Used For: Storytelling, creative writing
Examples:
- In olden days, people traveled mostly by horse and carriage.
- In olden days, children played outside without any screens at all.
Antonyms of Once
| # | Antonym | Simple Meaning | Example |
| 1 | Now | At the present time | She works as a doctor now, not a teacher. |
| 2 | Currently | Happening at this present time | He is currently living in a different city. |
| 3 | Presently | At this time, right now | Presently, the store is closed for renovations. |
| 4 | Nowadays | In the present time, compared to the past | Nowadays, most people shop online. |
| 5 | Still | Continuing up to the present time | She still lives in the same house from years ago. |
Words Commonly Confused with Once
Once vs. Ones
Difference: Once refers to time, meaning “one time” or “formerly,” while ones is the plural form of “one,” referring to objects or people.
Example: Once, we owned three cars, but now we only have two ones left. (Correct usage: “we only have two.”)
Formerly vs. Former
Difference: Formerly is an adverb describing when something happened, while former is an adjective describing a previous role or state.
Example: He is the former mayor, and he formerly worked as a lawyer.
Previously vs. Prior
Difference: Previously is an adverb meaning “before now,” while prior is an adjective usually followed by “to,” meaning “before a specific event.”
Example: Prior to the meeting, she had previously reviewed the report.
Once (adverb) vs. Once (conjunction)
Difference: As an adverb, once means “at an earlier time.” As a conjunction, once means “as soon as” or “after.”
Example: Once she finishes her homework, she can watch TV. (conjunction) / She once lived in Spain. (adverb)
Back then vs. Back now
Difference: Back then refers to a past time, while “back now” is not a standard phrase; “now” alone is used to mean the present.
Example: Back then, we didn’t have smartphones, but we do now.
FAQs
What is another word for once?
Common alternatives include formerly, previously, at one time, and in the past. “Formerly” and “previously” work well in formal writing, while “at one time” and “back then” fit casual conversation.
What is the closest synonym for once?
“Formerly” is the closest synonym because it carries almost the same meaning, describing something that was true before but isn’t true anymore.
Can I replace “once with “previously”?
Yes, in most cases. Both words describe something that happened before now. “Previously” often sounds slightly more formal and works well in reports, essays, and professional writing.
Is once formal or informal?
Once is a neutral word. It works in casual conversation, storytelling, and formal writing, making it one of the most flexible words for talking about the past.
What is the opposite of once?
There’s no single perfect opposite, but related contrasting ideas include now, currently, and nowadays, all of which describe the present instead of the past.
Which synonym is best for storytelling?
“In olden days,” “of yore,” and “in days gone by” all work well for storytelling because they create a nostalgic, old-fashioned feeling that suits fairy tales and folk stories.
Conclusion
Learning synonyms for once helps you avoid repeating the same word when talking or writing about the past. It also lets you match your tone, whether that’s formal, casual, or storybook-style.
Context matters here too. A business report calls for “formerly” or “previously,” while a bedtime story might call for “once upon a time” or “in olden days.”
Try using a few of these words the next time you write an email, tell a story, or describe how things used to be. Small changes like this can make your writing feel more natural and engaging.
