# once

/ˈwəns/ (US) · /wˈɒns/ (UK)

Source: https://englishreference.com/word/once
Updated: 2026-06-19

## Senses

### 1. one time only

adverb · CEFR A1

one time and only one time.

For teachers: on a single occasion; one time only.

- I have only been to Paris once, but I would love to go back.
- The medication should be administered once every twenty-four hours to maintain a consistent level in the bloodstream.

Usage: Usually placed after the verb or at the end of a clause.

### 2. in the past

adverb · CEFR A2

at a time in the past but not anymore.

For teachers: at a former time; formerly.

- This building was once a school, but now it is a library.
- The region was once a thriving industrial hub, though it has since transitioned into a service-based economy.

Usage: Often used to introduce stories or to describe a state that has changed.

### 3. multiplied by one

adverb · CEFR B2 · Technical

multiplied by the number one.

For teachers: indicating that a quantity is multiplied by one.

- Any number multiplied once by itself remains the same.
- The formula requires the variable to be factored once before the final calculation is performed.

Usage: Used in mathematical contexts to define identity or frequency.

### 4. as soon as

conjunction · CEFR B1

as soon as or after something happens.

For teachers: as soon as; at the moment that.

- Once you finish your homework, you can go outside and play.
- Once the contract has been signed by both parties, the initial deposit will be transferred to the escrow account.

Usage: Used to join two clauses; the 'once' clause usually happens first.

### 5. fan of the band Twice

noun · CEFR C1 · Slang

a name for a fan of the famous music group called Twice.

For teachers: a member of the official fandom for the South Korean girl group Twice.

- She has been a dedicated Once since the band first started.
- Thousands of Onces gathered outside the stadium hours before the concert began, trading photocards and singing along to the group's latest hits.

Teaching tip: This is a very specific cultural term used by fans of K-pop; it is not used in general or formal English.

## Examples

- I only met him once at a party.
- The software requires you to enter the activation code once during the initial setup process.
- While the experiment was performed multiple times to ensure accuracy, the specific chemical reaction being studied occurred only once under those exact atmospheric conditions.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.