brother-in-law

noun

broth·​er-in-law ˈbrə-t͟hər-ən-ˌlȯ How to pronounce brother-in-law (audio)
ˈbrət͟h-rən-,
ˈbrə-t͟hərn-
plural brothers-in-law ˈbrə-t͟hərz-ən- How to pronounce brother-in-law (audio)
1
: the brother of one's spouse
2
a
: the husband of one's sibling
b
: the husband of one's spouse's sibling

Examples of brother-in-law in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
After the seventh episode, Jenny's brother-in-law rushed him to the only 24-hour vet clinic available in the area. Alice Gibbs, MSNBC Newsweek, 19 July 2025 Nadler’s grandfather had died due to a medical error, while Ziegler had watched his brother-in-law, then 22, go through treatment for leukemia. Amy Feldman, Forbes.com, 15 July 2025 Baciu, Herman's brother-in-law (having married Herman's oldest sister), was the chief construction officer. ArsTechnica, 14 July 2025 After calling Jake and his sister, Ramsey called his brother-in-law and his mother, who were staying in a cabin 100 yards away, according to ABC News. Fort Worth Star-Telegram, 13 July 2025 See All Example Sentences for brother-in-law

Word History

First Known Use

14th century, in the meaning defined at sense 1

Time Traveler
The first known use of brother-in-law was in the 14th century

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Cite this Entry

“Brother-in-law.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/brother-in-law. Accessed 24 Jul. 2025.

Kids Definition

brother-in-law

noun
broth·​er-in-law
ˈbrət͟h-(ə-)rən-ˌlȯ,
ˈbrət͟h-ərn-ˌlȯ
plural brothers-in-law
ˈbrət͟h-ər-zən-
1
: the brother of one's spouse
2
: the husband of one's sibling or of one's spouse's sibling

More from Merriam-Webster on brother-in-law

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