sis·​ter | \ ˈsi-stər How to pronounce sister (audio) \

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 Additionally, federal funds from both Mexico and the U.S. have been approved to renovate the port of entry of Agua Prieta, Sonora, and Douglas, Arizona, and build a new commercial one, west of the sister border cities. Clara Migoya, The Arizona Republic, 23 Jan. 2022 Meanwhile, Facebook and sister company Instagram are working on a feature that will let users display NFTs as part of their profiles, the Financial Times reported. Washington Post, 22 Jan. 2022 Lola's is the sister business of Antigua Restaurant, 6207 W. National Ave. Bob Dohr, Milwaukee Journal Sentinel, 22 Jan. 2022 When her mom and sister pass a blunt around, Sarah Jo eats ice cream. Jourdain Searles, The Hollywood Reporter, 22 Jan. 2022 In the film, Music (Ziegler) is a young autistic woman who falls under the care of her half-sister Zu (Kate Hudson) after her grandmother dies (Mary Kay Place). Amy Haneline, USA TODAY, 21 Jan. 2022 The class also got to virtually meet Cinsere's new baby sister. Madeline Mitchell, The Enquirer, 21 Jan. 2022 Her soups this season will honor late owner Karen Gerod, a longtime friend and supporter of Soup & Bread, courtesy of sister Debra Gerod. Louisa Chu,, 20 Jan. 2022 Skelley examines presidential approval ratings for FiveThirtyEight, a sister company of ABC News. Cristina Corujo, ABC News, 20 Jan. 2022

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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Time Traveler for sister

Time Traveler

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

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Dictionary Entries Near sister



sister block

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Statistics for sister

Last Updated

24 Jan 2022

Cite this Entry

“Sister.” Dictionary, Merriam-Webster, Accessed 27 Jan. 2022.

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More Definitions for sister



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 : nun


sis·​ter | \ ˈsi-stər How to pronounce sister (audio) \

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 How to pronounce sister (audio) \

Medical Definition of sister

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


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