Once

/wʌn(t)s/ adv, conj, noun, slang

adv, conj, noun, slang ·Common ·High school level

Meaning at a glance

  • Primary sense: Obsolete form of ounce.
  • Grammar: once is listed as adv, conj, noun, slang.
  • Nearest alternatives: erstwhile, formerly, after, alone.
  • Useful contrasts: tenfold, threefold, four times.
  • Usage evidence: I once wanted to be an astrophysicist.

How to use "once"

  1. Start with the primary definition, then check the part of speech before placing the word in a sentence.
  2. Compare nearby synonyms to make sure "once" carries the exact meaning, tone, and strength you need.
  3. Use the example sentence as a context check. If your sentence uses the word differently, confirm that the grammar still fits.

Meaning check

  • Does the word fit the sentence's grammar?
  • Does it match the intended tone rather than only the dictionary definition?
  • Would a simpler synonym be clearer for the reader?
  • Is there enough surrounding context to prevent ambiguity?

Source and review context

This entry combines structured lexical data with WordToolSet review checks. Definitions, examples, synonyms, and usage notes may come from different source tables, so the page is designed to show evidence from more than one angle before you rely on "once" in a final draft.

If a word has several senses, prefer the sense that matches your sentence's grammar and surrounding context. A correct definition can still be the wrong choice when the sentence needs a different register, emphasis, or level of specificity.

Before you rely on this definition

Read the first definition as a starting point, then check the example, synonyms, and part of speech before treating "once" as the right word for your sentence.

If your draft is formal, technical, persuasive, or sensitive, compare "once" with a nearby alternative so the final choice matches both meaning and reader expectation.

Compare nearby meanings

  • Use synonyms when you need a softer, stronger, simpler, or more specific word.
  • Use antonyms to check the boundary of the meaning and avoid accidental contrast.
  • Use the example sentence to confirm the word behaves naturally in context.
  • Keep the original wording when a replacement adds complexity without improving precision.

Definition decision workflow

1. Identify the role

Check whether "once" is acting as adv, conj, noun, slang in your sentence. A definition is only useful when the grammar matches the way the word is being used.

2. Test the nearest option

Compare it with "erstwhile" and other nearby choices to see whether the sentence needs a softer, stronger, or more familiar word.

3. Confirm with context

Use the example sentence below as an evidence check, then read your own sentence out loud to catch tone or rhythm problems.

Review note: Definition pages are checked for source coverage, sentence evidence, synonym support, and editorial insight before they are treated as approval-ready pages. If the evidence is too thin, the page remains available to users but is kept out of the approval-facing indexed inventory.

Final meaning check

Before publishing a sentence with "once", ask whether the word helps the reader understand the idea faster. A precise word should reduce confusion, not simply make the sentence look more polished.

When the definition, synonym evidence, and example context point in the same direction, the word is usually a safer choice. When they conflict, revise the sentence or choose a clearer alternative.

Definitions

Noun
  1. 1
    Obsolete form of ounce. alt-of, obsolete
  2. 2
    A fan of the Korean girl band Twice. slang
Adverb
  1. 1
    One and only one time. not-comparable

    "I have only once eaten pizza."

  2. 2
    Formerly; during some period in the past. not-comparable

    "He was once the most handsome man around."

  3. 3
    At any time; ever. not-comparable, obsolete

    "The wisdom of God thought fit to acquaint David with that court which we shall once govern."

  4. 4
    One day, someday. not-comparable, obsolete
  5. 5
    Multiplied by one: indicating that a number is multiplied by one. not-comparable

    "Once three is three."

Adverb
  1. 1
    on one occasion wordnet
  2. 2
    at a previous time wordnet
  3. 3
    as soon as wordnet
Conjunction
  1. 1
    As soon as; when; after.

    "Near-synonym: immediately"

Antonyms

Example

"I once wanted to be an astrophysicist."

Common questions

What does "once" mean?

Obsolete form of ounce.

What is a synonym for "once"?

Common synonyms include: erstwhile, formerly, after, alone, already, ancient.

How do you use "once" in a sentence?

I once wanted to be an astrophysicist.

How do you pronounce "once"?

Pronounced /wʌn(t)s/.

Etymology

From Middle English ones, from Old English ānes, a remodelling (after ān (“one”)) of ǣnes, itself an extension of ǣne (“once”) with the genitive suffix -es. Compare Old Saxon ēnes (“once”), Old High German eines, einēst (“once”), modern German einst (“once”). More at one (including regarding the development of the pronunciation) and -s.

More for "once"