parenthesis

American  

[puh-ren-thuh-sis] / pəˈrɛn θə sɪs /

noun

parentheses plural

1. either or both of a pair of signs ( ) used in writing to mark off an interjected explanatory or qualifying remark, to indicate separate groupings of symbols in mathematics and symbolic logic, etc.

2. Usually parentheses. the material contained within these marks.

3. Grammar. a qualifying, explanatory, or appositive word, phrase, clause, or sentence that interrupts a syntactic construction without otherwise affecting it, having often a characteristic intonation and indicated in writing by commas, parentheses, or dashes, as in William Smith—you must know him—is coming tonight.

4. an interval.

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parenthesis British  

/ ˌpærənˈθɛtɪk, pəˈrɛnθɪsɪs /

noun

1. a phrase, often explanatory or qualifying, inserted into a passage with which it is not grammatically connected, and marked off by brackets, dashes, etc

2. Also called: bracket.  either of a pair of characters, (), used to enclose such a phrase or as a sign of aggregation in mathematical or logical expressions

3. an intervening occurrence; interlude; interval

4. inserted as a parenthesis

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Other Word Forms

Derived Forms

• parenthetic
  adjective
• parenthetically
  adverb

Inflected Forms

Nouns

• parentheses
  plural

Etymology

Origin of parenthesis

1560–70; < Late Latin < Greek parénthesis a putting in beside. See par-, en- ², thesis

Explanation

A parenthesis is a tall, curvy punctuation mark used to set off material that isn’t fundamental to the main topic, like an afterthought or an aside (or a funny joke). Parenthesis marks come in pairs: the plural is spelled “parentheses.” Parentheses look like this: ( ). When you use parentheses to set off material in a sentence, you say that the material is “in parenthesis.” Put something in parentheses if it's a comment, an afterthought, or additional information that is possibly interesting but not essential to the subject. You can also describe something as a parenthesis, like a digressive story about horses in the middle of a political speech.

Example Sentences

See Examples For:

parenthesis parentheses

Whereas if it were ‘natural flavor’ and then in parenthesis a long list of bizarre chemical names, you might think twice about eating it.

From Salon ● Apr. 14, 2024

That’s where it started off with the parenthesis; it was marking a sense of time passing but also emphasizing the single exposure.

From Los Angeles Times ● Mar. 15, 2023

"They should have made a parenthesis in the subtitles when the North Korean character speaks," She said.

From Fox News ● Oct. 6, 2021

Because the number 3 itself is not a solution, we put an open parenthesis at 3.

From Textbooks ● Apr. 22, 2020

Life is not a paragraph, and death is no parenthesis.

From "The Girl on the Train" by Paula Hawkins

It’s less jarring than parentheses but a bigger interruption than commas.

From The Wall Street Journal ● Nov. 20, 2025

They are listed in ascending order of their trailing-month returns, which are displayed in the parentheses.

From MarketWatch ● Nov. 10, 2025

Unlike periods and commas, em dashes aren’t integral to sentence structure; they’re a considered choice that can, but by no means have to, take the place of commas, parentheses and semicolons.

From Salon ● Jun. 11, 2025

Figures in parentheses reflect the number of times a book was checked out.

From Seattle Times ● Dec. 25, 2023

Letters were multiplied by symbols, crowded into parentheses, and set upon by dwarfish numbers drawn at odd angles.

From "Me Talk Pretty One Day" by David Sedaris