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

Investigators don’t know what happened to the two girls after Moore and his brother-in-law dropped them off. — Sarah Dahlberg, NBC news, 3 Nov. 2026

Letter writer didn’t invite aggressive brother-in-law to husband’s 50th birthday party. — R. Eric Thomas, Washington Post, 2 Nov. 2026

Jessie told followers to scroll to the last slide, which featured her brother-in-law, Anthony Bass — who was dressed as Spider-Man, picking her up and running away. — Entertainment Weekly, 2 Nov. 2026

Then, on October 26, a member of Parliament—who happened to be the brother-in-law of one of the conspirators—received a cryptic, anonymous letter. — Lucia Barnum, Encyclopedia Britannica, 29 Oct. 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