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:
For instance, Mr. Nichols tells us early on that Hawthorne’s sister-in-law, Elizabeth Peabody, coined the word “transcendentalism.”
From The Wall Street Journal ● Aug. 14, 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
Your sister-in-law may just be a bit flaky.
From MarketWatch ● Aug. 7, 2026
She then warned her sister-in-law Georgia, whose family had been due to join them in the Bordeaux region in Lacanau, not to come.
From BBC ● Jul. 27, 2026
“My wife and sister-in-law have heart trouble and I'll assure you had this horrifying program been fatal to either of them the Columbia Company would have had to answer for it.”
From "Spooked!" by Gail Jarrow
BBC Urdu's Tarhub Asghar met two sisters-in-law, both nine months pregnant.
From BBC ● Nov. 1, 2025
She exchanged postcards with former sisters-in-law and her first husband’s second wife.
From Salon ● Feb. 9, 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
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.
