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

The widow of Peter Seidler, who died at 63 more than a year ago, filed suit against brothers-in-law Matthew and Robert Seidler earlier this week. —Dan Schlossberg, Forbes, 8 Jan. 2025

Peter said his brother-in-law left the home before police were called. —Liam Quinn, People.com, 6 Jan. 2025

Your brother-in-law should not have invited anyone along without clearing it with you first. —Jeanne Phillips, The Mercury News, 4 Jan. 2025

Bob Breitenstein sold the bar to McClelland and his brother-in-law Johnathan Griffiths in December after more than 20 years. —Allison Dikanovic, Kansas City Star, 2 Jan. 2025

Word History

First Known Use

14th century, in the meaning defined at sense 1

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