mother-in-law

noun

moth·​er-in-law ˈmə-t͟hər-ən-ˌlȯ 

ˈmət͟h-rən-, 

ˈmə-t͟hərn-

plural mothers-in-law ˈmə-t͟hər-zən-ˌlȯ 

1

: the mother of one's spouse

2

archaic : stepmother

Examples of mother-in-law in a Sentence

Recent Examples on the Web

Swift's soon-to-be mother-in-law, 73, arrived in the city on Thursday, July 2, amid reports that a wedding rehearsal dinner would occur later that night, according to People. — Bryan West, USA Today, 4 July 2026

Today, my children lost their father, my mother-in-law lost her son, my siblings lost their brother. — Kimberlee Speakman, PEOPLE, 2 July 2026

Kate Middleton shares her mother-in-law’s penchant for pearls, and has been spotted sporting several of Diana’s pearl pieces. — Hadley Hall Meares, Vanity Fair, 26 June 2026

The Princess of Wales loves her sapphires, just like her mother-in-law did! — Bailey Bujnosek, InStyle, 26 June 2026

Word History

First Known Use

14th century, in the meaning defined at sense 1

Rhymes for mother-in-law

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

Kids Definition

mother-in-law

noun

moth·​er-in-law

ˈmət͟h-(ə-)rən-ˌlȯ, 

ˈmət͟h-ərn-ˌlȯ

plural mothers-in-law

ˈmət͟h-ər-zən-

: the mother of one's husband or wife