sister
Americannoun
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sisters
plural
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a female offspring having both parents in common with another offspring; female sibling.
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Also called half sister. a female offspring having only one parent in common with another offspring.
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a female friend or protector regarded as a sister.
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a thing regarded as feminine and associated as if by kinship with something else.
The ships are sisters.
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a female fellow member, as of a church.
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a female member of a religious community that observes the simple vows of poverty, chastity, and obedience.
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British. a nurse in charge of a hospital ward; head nurse.
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Informal. a term used to refer to or address a fellow Black woman; soul sister.
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a woman who supports, promotes, or participates in feminism.
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Informal. a form of address used to a woman or girl, especially jocularly or contemptuously.
Listen, sister, you've had enough.
adjective
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being or considered a sister; related by or as if by sisterhood.
sister ships.
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having a close relationship with another because of shared interests, problems, or the like.
We correspond with school children in our sister city.
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Biochemistry. being one of an identical pair.
noun
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a female person having the same parents as another person
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a female person who belongs to the same group, trade union, etc, as another or others
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informal a form of address to a woman or girl, used esp by Black people in the US
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a senior nurse
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RC Church a nun or a title given to a nun
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a woman fellow member of a Church or religious body
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(modifier) belonging to the same class, fleet, etc, as another or others
a sister ship
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(modifier) biology denoting any of the cells or cell components formed by division of a parent cell or cell component
sister nuclei
Other Word Forms
Derived Forms
Inflected Forms
Nouns
Etymology
Origin of sister
First recorded before 900; Middle English (noun) from Old Norse systir; cognate with Old English sweoster, Dutch zuster, German Schwester, Gothic swistar; akin to Serbo-Croatian sèstra, Lithuanian sesuõ, Latin soror (from unattested swesor ), Old Irish siur, Welsh chwaer, Sanskrit svasar “sister,” Greek éor “daughter, niece”
Explanation
Your sister is your female sibling. If your parents have six children, and all of them are girls, that means you have five sisters. Your biological sister has the same mother and father that you have, but some sisters are adopted, or even have a different mom or dad (some people call this a stepsister or a half-sister). If you join a college sorority or a trade union, you'll refer to the other members as your sisters. Catholic nuns and other religious women are also called sisters. The roots of sister go back to words meaning "one's own" and "woman."
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
The daughter of a nuclear submarine captain in Ledyard, Conn., she and her sister were expected to defend their positions at the dinner table.
From The Wall Street Journal ● Aug. 28, 2026
But there is no limit to the number of wildcards a Grand Slam champion can receive and, for many tournaments, having a Williams sister on site still makes commercial sense.
From BBC ● Aug. 28, 2026
This week, there was a major breakthrough when DNA provided by her sister, Burks, was determined to be a match, enabling investigators to finally identify the 1995 victim as Lydia.
From Los Angeles Times ● Aug. 28, 2026
Samba and her sister Rose were born at the sanctuary 14 years ago.
From Los Angeles Times ● Aug. 27, 2026
“My mom and older sister made these. I’m in charge of selling them. We’re raising money for the Elder care program. We want to get them stuff for arts and crafts and activity nights.”
From "Legendary Frybread Drive-In" by Cynthia Leitich Smith
Her sisters, Alyssa and Gisele, signed a deal when they were in high school.
From Los Angeles Times ● Aug. 28, 2026
The region's hardscrabble existence is perhaps best illustrated in Dollywood's full-size replica of the humble two-room log cabin where Parton grew up with her 11 brothers and sisters in Locust Ridge, outside Sevierville.
From Barron's ● Aug. 26, 2026
Andrea and I still clashed, as vastly different Type-A sisters do.
From Los Angeles Times ● Aug. 26, 2026
In May, three sisters, Jane Adetoro, 36, Christina Walters, 32, and Rebecca Walters, 31, died in the sea off Brighton, in what police described as a "tragic incident".
From BBC ● Aug. 19, 2026
In 1902, the sisters marched into the Board of Control, the governing body for the home, and demanded more funds.
From "At Last She Stood" by Erin Entrada Kelly
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
