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

After Diana’s engagement ring became an instant classic, her sister-in-law Sarah Ferguson also bucked the diamond tradition, choosing a three-carat Burmese ruby surrounded by diamonds in a floral design. — Hadley Hall Meares, Vanity Fair, 6 July 2026

After leaving Nashville, the plane flew to Philadelphia, where Travis’ dad, Ed, lives, as well as his brother, Jason, and his sister-in-law, Kylie. — Jason Pham, StyleCaster, 3 July 2026

Cancro’s wife, two sons, daughter, sister-in-law, brother, two brothers-in-law, and stepson all drew patches from the company at various points between 2023 and 2025. — Antonio Pequeño Iv, Forbes.com, 2 July 2026

No offense to anyone, but having your sister-in-law as your maid of honor is insane behavior. — Hannah Vanbiber, New York Times, 2 July 2026

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