sister-in-law
Americannoun
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sisters-in-law
plural
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the sister of one's spouse.
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the wife of one's brother or sister.
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the wife of one's spouse's sister or brother.
noun
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the sister of one's husband or wife
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the wife of one's brother
Other Word Forms
Noun Inflected Forms
Etymology
Origin of sister-in-law
First recorded in 1400–50; late Middle English syster in lawe; see origin at sister, in, law 1; from Middle English in-lawe “in law,” i.e., “a person within the regulation and protection of the law,” based on the prohibition by Roman civil law and, later, Christian canon law, of marriages within four degrees of consanguinity, i.e., up to and including first cousins
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:
Emmanuel Banuelos spent weeks planning the perfect proposal, selecting a picturesque spot at a Laguna Beach park, enlisting his soon-to-be sister-in-law as a videographer and booking a mariachi band to play his girlfriend’s favorite music.
From Los Angeles Times ● Oct. 5, 2026
His former sister-in-law told the BBC that she did not know where he was, and nobody had been able to see him.
From BBC ● Sep. 29, 2026
In her “wife school” series, Clark interviewed her new sister-in-law, Katie Voetberg, a prairie dress-clad podcast host and mother of six, about how to avoid being a “nagging wife” and a “constant dripping faucet.”
From Salon ● Sep. 28, 2026
My grandmother now wants to revise her will to include my sister, her five great-grandchildren, my sister-in-law, and me.
From MarketWatch ● Aug. 20, 2026
Bayard, who was married to Elizabeth’s sister Tryphena, had been very close to his sister-in-law; they had enjoyed spending time together, reading novels, riding horses, and discussing philosophy and law.
From "Votes for Women!" by Winifred Conkling
She exchanged postcards with former sisters-in-law and her first husband’s second wife.
From Salon ● Feb. 9, 2025
"My father, my brother, my sisters-in-law and my friends are gone," says Delfino.
From BBC ● Feb. 7, 2025
Keona’s mother, Rochelle, whispered to her sisters-in-law in Filipino.
From Los Angeles Times ● Aug. 21, 2023
Stuck, uncomfortably, in the middle, is Sasha, the middle-class New England girl who has married their brother, Cord, and, despite all signs to the contrary, is referred to as “the Gold Digger” by her sisters-in-law.
From New York Times ● Feb. 26, 2023
Patti starts pointing out faces and naming my father's cousins and their sisters and sisters-in-law and brothers and brothers-in-law.
From "Born Behind Bars" by Padma Venkatraman
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Get a wordDefinitions 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.
