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

Her sister-in-law, Allison Otto, is president and CEO of Otto Construction. —Graham Womack, Sacbee.com, 20 June 2026

After receiving evidence that his son is still actually alive, David teams up with his ex-sister-in-law, Rachel Mills (Britt Lower). —Ralphie Aversa, USA Today, 18 June 2026

Everything changes when his former sister-in-law, Rachel Mills (Britt Lower), visits him in prison with evidence suggesting his child may still be alive. —Dana Feldman, Forbes.com, 18 June 2026

Also in attendance were Princess Kate's mother, Carole Middleton, and her sister-in-law, Alizee, who is married to her brother James Middleton. —Stephanie Petit, PEOPLE, 17 June 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