sister-in-law

noun

sis·​ter-in-law ˈsi-st(ə-)rən-ˌlȯ 

-tərn-ˌlȯ

plural sisters-in-law ˈsi-stər-zən-ˌlȯ 

1

: the sister of one's spouse

2

a

: the wife of one's sibling

b

: the wife of one's spouse's sibling

Examples of sister-in-law in a Sentence

Recent Examples on the Web

My mother-in-law and sister-in-law wore white gowns to my wedding. —Judith Martin, Mercury News, 25 Apr. 2025

My sister-in-law, a mom of one, wants this kids’ artwork frame that matches her home’s decor, and another mom friend swears by this flowy maxi dress for any occasion. —Jacquelyn Smith, Parents, 24 Apr. 2025

In the season première, a cynical Joel chided Jackson’s mayor, Maria (Rutina Wesley), who happens to be his sister-in-law, for straining the town’s limited resources by welcoming strangers with open arms. —Inkoo Kang, New Yorker, 20 Apr. 2025

The two sisters-in-law were unaware that the LAPD was wrapping up their case against Monica Sementilli and Baker. —Greg Fisher, CBS News, 14 Apr. 2025

Word History

First Known Use

15th century, in the meaning defined at sense 1

Rhymes for sister-in-law

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

Kids Definition

sister-in-law

noun

sis·​ter-in-law

ˈsis-t(ə-)rən-ˌlȯ,

-tərn-ˌlȯ

plural sisters-in-law

-tər-zən-

1

: the sister of one's spouse

2

a

: the wife of one's sibling

b

: the wife of one's spouse's sibling