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

Tony Romo refers to Jason Kelce as Taylor Swift's brother-in-law. —Pete Grathoff, Kansas City Star, 4 Feb. 2026

Police have responded to claims that Savannah Guthrie’s brother-in-law, Tommaso Cioni, was a prime suspect in the disappearance of her mother, Nancy. —Lea Veloso, StyleCaster, 4 Feb. 2026

Annie's husband, and Savannah's brother-in-law, is Tommaso Cioni, according to Page Six, which published photographs of the pair leaving their home in Tucson. —Brendan Morrow, USA Today, 4 Feb. 2026

My mother never smoked, but her brother-in-law, my uncle Leo, brought the cigarette holder back after World War II as a gift. —Danielle Parker, CBS News, 3 Feb. 2026

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