brother-in-law

noun

broth·​er-in-law ˈbrə-t͟hər-ən-ˌlȯ 

ˈbrət͟h-rən-, 

ˈbrə-t͟hərn-

plural brothers-in-law ˈbrə-t͟hərz-ən- 

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

Hudson’s brother-in-law at the time, William Balfour, was the gunman and killed Hudson's mother, her brother Jason Hudson and her 7-year-old nephew Julian, the son of his estranged wife, Hudson's sister Julia. —Yamillah Hurtado, PEOPLE, 10 Nov. 2025

However, her brother-in-law is hestitant. —Stylecaster Editors, StyleCaster, 9 Nov. 2025

The newest wellness trend that has everyone—from your pilates instructor to your brother-in-law—obsessing? —Brianna Peters, Vogue, 9 Nov. 2025

The Swiss paid commissions of $12 million to two companies in the British Virgin Islands owned by Bhutto’s husband and brother-in-law. —Rafia Zakaria, Time, 6 Nov. 2025

Word History

First Known Use

14th century, in the meaning defined at sense 1

Rhymes for brother-in-law

• avoirdupois
• aa
• aha
• bashaw
• bradshaw
• byelaw
• bylaw
• chainsaw
• cheraw
• coleslaw
• crenshaw
• dada

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