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Synonyms

sister-in-law

American  
[sis-ter-in-law] / ˈsɪs tər ɪnˌlɔ /

noun

plural

sisters-in-law
  1. the sister of one's spouse.

  2. the wife of one's brother or sister.

  3. the wife of one's spouse's sister or brother.


sister-in-law British  

noun

  1. the sister of one's husband or wife

  2. the wife of one's brother

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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.

Her sister in law, Yarden Roman-Gat, was released by Hamas on Wednesday, and reunited with her husband and three-year-old daughter.

From BBC • Dec. 1, 2023

The New York Times reported Thursday, based on a text message from Crosby’s sister in law, that the musician died Wednesday night.

From Seattle Times • Jan. 19, 2023

The elder Taylor on Tuesday said a cousin of Ghosn, who is his wife’s sister in law, helped persuade him to take the job.

From Reuters • Jun. 29, 2021

“That’s his smile,” said Jeanmarie Larsen, Cuffe’s sister in law.

From Washington Times • Nov. 29, 2019

And she said, Behold, thy sister in law is gone back unto her people, and unto her gods return thou after thy sister in law.

From The Doré Gallery of Bible Illustrations, Volume 3 by Doré, Gustave

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