sister

noun

sis·​ter ˈsi-stər 

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

3

a

: 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

6

a

: 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

Ferguson’s sister, Amanda Ferguson, confirmed to NBC News on Friday their mother is Mona Hartling and the person listed as M.H. in the complaint. —Antonio Planas, NBC News, 2 Dec. 2023

The firm is part of an alliance headed by the San Francisco Conservatory of Music which includes sister artist management company Askonas Holt and recording label Pentatone. —Marc Schneider, Billboard, 1 Dec. 2023

In addition to his wife, Mr. MacGowan is survived by his sister, Siobhan, and his father, Maurice. —Matt Phillips, New York Times, 30 Nov. 2023

Kourtney asked while sitting beside her mom and sister Khloé Kardashian. —Joelle Goldstein, Peoplemag, 30 Nov. 2023

While the 21-year-old comes from a showbiz family—mom Leslie Mann and sister Maude Apatow are also actors, while dad Judd Apatow is a director—she’s also known for her immaculate taste: Apatow’s retro LA apartment was featured in Architectural Digest. —Monique Wilson, Glamour, 30 Nov. 2023

While on the show, Spears also discussed her strained relationship with her older sister, Britney Spears. —Carlos De Loera, Los Angeles Times, 29 Nov. 2023

In 2014, Packer and his sister, Gretel, pledged A$100 million from the family’s foundation and A$100 million from Crown’s philanthropic arm over ten years to support art organizations, indigenous education and other community initiatives. —Rana Wehbe Watson, Forbes, 29 Nov. 2023

Verina Astra’s sister establishment, Verina Terra, is located in Platys Gialos, the largest and most cosmopolitan beach on the island. —Jordan Riefe, The Hollywood Reporter, 19 Nov. 2023

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Word History

Etymology

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

First Known Use

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

Phrases Containing sister

• big sister
• little brother/sister
• sister city
• brother/sister/comrade in arms
• foster brother/sister
• sister chromatid
• sister-in-law
• weak sister
• sob sister
• half sister
• soul sister

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• big sister
• little brother/sister
• sister city
• brother/sister/comrade in arms
• foster brother/sister
• sister chromatid
• sister-in-law
• weak sister
• sob sister
• half sister
• soul sister

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Kids Definition

sister

noun

sis·​ter ˈsis-tər 

1

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

2

often capitalized : a member of a religious community of women : nun

3

a

: a fellow female member of a group

b

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

4

: one that is closely similar to or associated with another

sister schools

sister ships

5

chiefly British : nurse entry 1 sense 2

sisterly adjective or adverb

Medical Definition

sister

noun

sis·​ter ˈsis-tər 

chiefly British

: a head nurse in a hospital ward or clinic

broadly : nurse