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

In her late mother-in-law's likeness, Kate showed off her baby bump on June 15, 2013—just one month before her and William's first child, Prince George, was born on July 22, 2013. —Christina Perrier, InStyle, 13 June 2026

For the annual occasion, the princess opted for a powder-blue and white ensemble with matching hat – a sweet tribute to her late mother-in-law, Princess Diana, who wore an almost identical outfit in 1987. —Morgan Evans, USA Today, 13 June 2026

Jackie's soon-to-be mother-in-law channels all her resentment and rage into breaking up her son's engagement by becoming an absolute terror. —Britt Hayes, Entertainment Weekly, 12 June 2026

Laura Bush did it entirely differently than her mother-in-law, Barbara Bush. —Julia Terruso, Time, 11 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