# parenthesis

/pɝˈɛnθəsɪs/ (US) · /pəɹˈɛnθəsˌɪs/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/parenthesis
Updated: 2026-10-16

## Definition

one of the two curved marks ( ) that you put around extra words or numbers in a sentence. You use it to add small extra information without breaking the main idea.

For teachers: one of a pair of curved brackets ( ) used to enclose supplementary words, figures, or clauses within a sentence or expression. By extension, refers to the inserted aside itself.

## Examples

- She adds a parenthesis to explain the date.
- The teacher puts the extra detail in a parenthesis so the main sentence stays clear.
- The editor removes the parenthesis around the birth year to let the sentence flow without interruption.

## Pitfalls

- Not "a parentheses to explain" but "a parenthesis to explain" — Parenthesis is singular; parentheses is the plural form.

## Usage notes

- Plural is 'parentheses'; the plural often refers to the pair of marks together.

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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.