Dictionary.com
Thesaurus.com
Synonyms

sister-in-law

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

noun

  • sisters-in-law
    plural
  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

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:

Six of Tamang's relatives - his mother, elder brother and sister-in-law and three of their children - are gone, he said.

From BBC Sep. 1, 2026

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

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

I confirmed that she was deceased and explained that I was only her former sister-in-law.

From MarketWatch Jul. 31, 2026

Dimple’s face paled at the Hindi word for sister-in-law, and Rishi rushed to correct Ashish.

From "When Dimple Met Rishi" by Sandhya Menon

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

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

Moreno's wife, one of their daughters, two of his brothers and two sisters-in-law are also among those allegedly connected to the case, Salazar said.

From Reuters Feb. 22, 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

Vocabulary.com logo
by dictionary.com

Look it up. Learn it forever.

Remember new words for good with VocabTrainer. Expand your vocabulary effortlessly with personalized learning tools that adapt to your goals.

Take me to Vocabulary.com