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:
She was also Chiang’s sister-in-law, and though the two shared few political convictions, the family connection protected Soong even though she supported the couple.
From The Wall Street Journal ● Aug. 28, 2026
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
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
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
“You can’t have a daughter, since you abandoned her when she was little and went to war,” the sister-in-law argued.
From "A Thousand Sisters" by Elizabeth Wein
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She exchanged postcards with former sisters-in-law and her first husband’s second wife.
From Salon ● Feb. 9, 2025
Still, she and her husband and brothers- and sisters-in-law believed that God had a plan for them, even now, she said.
From Los Angeles Times ● Aug. 21, 2023
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
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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.