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:
Hivsa Walid told the BBC she was inside the hospital when the fire broke out, with her sister-in-law who had given birth in the days before.
From BBC ● Aug. 26, 2026
I’ve become really close with my sister-in-law, and almost every Sunday, we meet for what we call “tea time.”
From Los Angeles Times ● Aug. 7, 2026
Given your distant relationship with your former sister-in-law and the fact that your divorce was a difficult one, it seems unlikely that you were named as a beneficiary on her Fidelity account.
From MarketWatch ● Jul. 31, 2026
When they caught wind of the mysterious suitor, Danielle’s mom, sister and sister-in-law each found his LinkedIn page.
From The Wall Street Journal ● Jul. 1, 2026
And yet here she sits at the table, in labor, with her husband and mother and sister-in-law, writing to Vincent on a piece of cream-colored paper, in Dutch, with black ink.
From "Vincent and Theo: The Van Gogh Brothers" by Deborah Heiligman
She exchanged postcards with former sisters-in-law and her first husband’s second wife.
From Salon ● Feb. 9, 2025
His mother was ill, so one of her sisters-in-law filled out the registration card and submitted it to the city to produce a birth certificate, Didier Optowsky said.
From Los Angeles Times ● Apr. 26, 2024
I saw my wife and one of my sisters-in-law being swept away, followed by my elder brother.
From BBC ● Jun. 15, 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
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.
