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Synonyms

brother-in-law

American  
[bruhth-er-in-law] / ˈbrʌð ər ɪnˌlɔ /

noun

brothers-in-law plural
  1. the brother of one's spouse.

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

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


brother-in-law British  

noun

  1. the brother of one's wife or husband

  2. the husband of one's sister

  3. the husband of the sister of one's husband or wife

"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 brother-in-law

First recorded in 1350–1400; Middle English brother in law(e); see origin at brother, 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:

Grecia's body, located Thursday, was taken by her father to be cremated in Caracas, while Víctor awaited the remains of his nephews and brother-in-law.

From Barron's Jul. 4, 2026

Daniel Powers, Cancro’s brother-in-law, got around $30 million at that time, while Phillip Sivolobov, Cancro’s stepson, received total compensation of approximately $50 million.

From MarketWatch Jul. 2, 2026

He said he was there with his sister and brother-in-law but they couldn’t get inside.

From Los Angeles Times Jul. 1, 2026

"I lost my niece and my brother-in-law," she tells BBC Mundo.

From BBC Jun. 29, 2026

I was in a car with the brother-in-law of the son of the ruler of Arabia.

From "The Autobiography of Malcolm X" by Alex Malcolm X;Hailey

During the Civil War her brother George was a surgeon at a Confederate hospital, while three half-brothers and four brothers-in-law all supported the Confederacy.

From The Wall Street Journal May 11, 2026

Urfan's Pakistan-based family have taken Jhelum police to court twice, accusing them of detaining several of Urfan's brothers and brothers-in-law illegally.

From BBC Sep. 5, 2023

That’s when one of my brothers-in-law had to have surgery, to have some tumors removed in his brain.

From Seattle Times Aug. 4, 2023

While he was incarcerated, Theodora divorced him; she and their seven kids moved in with one of his brothers-in-law.

From Salon Feb. 28, 2023

I made my way to Gus’s parents in the living room and met his brothers-in-law, Chris and Dave.

From "The Fault in Our Stars" by John Green

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