sis·​ter | \ˈsi-stər \

Definition of sister 

1 : a female who has one or both parents in common with another

2 often capitalized

a : a member of a women's religious order (as of nuns or deaconesses) especially : one of a Roman Catholic congregation under simple vows

b : a girl or woman who is a member of a Christian church

3a : a girl or woman regarded as a comrade

b : a girl or woman who shares with another a common national or racial origin especially : a black girl or woman

4 : one that is closely similar to or associated with another sister cities

5 chiefly British : nurse

6a : girl, woman

b : person usually used in the phrase weak sister

7 : a member of a sorority

Examples of sister in a Sentence

The sisters live in the convent.

Recent Examples on the Web

However, Kate's excitement over the couple's future child seems to prove there are no hard feelings between her and her sister-in-law. Erica Gonzales, Harper's BAZAAR, "Kate Middleton Squashes Feud Rumors by Gushing Over Meghan Markle and Prince Harry's Baby," 28 Nov. 2018 One of the towers was for Pennzoil, the other was for its sister, Zapata Oil—the business founded by future president George H. W. Bush. Mark Lamster, Curbed, "Arbiter of taste, enfant terrible: The best and worst of Philip Johnson," 6 Nov. 2018 His parents’ business had helped put him and his sister through college. Bethany Biron, Vox, "The food court’s younger, hipper cousin is a curated version of the mall staple.," 30 Oct. 2018 Mary-Kate Olsen is often spotted wearing minimal, elegant ensembles from her and sister Ashley’s label The Row, but earlier this week at the American Gold Cup in North Salem, New York, the designer sported a different kind of uniform. Edward Barsamian, Vogue, "Mary-Kate Olsen Makes the Case for Classic Equestrian Style," 28 Sep. 2018 Whether Medusa or one of her sisters, the snake-hair is immediately recognizable. Hayden Dingman, PCWorld, "This week in games: Gabe Newell struggles with "triple kill" and BattleTech announces its first expansion," 24 Aug. 2018 My mom and sister still ask for pictures every day. Allure, "I Got Rhinoplasty at 25 — Here's What to Expect From a Nose Job," 7 Aug. 2018 She was predeceased by her son, Kenneth James Chapman, along with two brothers, and three sisters., "Evelyn Ruth Chapman," 14 July 2018 Charlotte Ann Burleigh Dissette, 95, beloved mother, sister, grandmother, great-grandmother, and aunt passed away peacefully at home on July 10, 2018., "Deaths in South Florida: 7/14," 14 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'sister.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of sister

before the 12th century, in the meaning defined at sense 1

History and Etymology for sister

Middle English suster, sister, partly from Old English sweostor and partly from Old Norse systir sister; akin to Latin soror sister, Sanskrit svasṛ

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Statistics for sister

Last Updated

16 Dec 2018

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Time Traveler for sister

The first known use of sister was before the 12th century

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English Language Learners Definition of sister

: a girl or woman who has one or both of the same parents as you

—used when talking to a woman

: a member of a religious community of women


sis·​ter | \ˈsi-stər \

Kids Definition of sister

1 : a female person or animal related to another person or animal by having one or both parents in common

2 : a member of a religious society of women : nun

3 : a woman related to another by a common tie or interest

Other Words from sister

sisterly adjective


sis·​ter | \ˈsis-tər \

Medical Definition of sister 

chiefly British

: a head nurse in a hospital ward or clinic broadly : nurse

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More from Merriam-Webster on sister

Rhyming Dictionary: Words that rhyme with sister

Spanish Central: Translation of sister

Nglish: Translation of sister for Spanish Speakers

Britannica English: Translation of sister for Arabic Speakers

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