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

Ray found a new-with-tags Guess winter coat for her mother-in-law for $8. —Betty Lin-Fisher, USA Today, 5 Dec. 2025

Choosing the earrings follows suit with Middleton’s tendency to honor her late mother-in-law through accessories and sartorial statements. —Julia Teti, Footwear News, 3 Dec. 2025

Initially, Doocy, 69, had prompted the father of four to share more about his mother-in-law playing a part in their introduction. —Lex Goldstein, PEOPLE, 3 Dec. 2025

Wilford, a longtime distance runner, laced up her running shoes this holiday season to honor her late mother-in-law, Ruth Wilford, and bring attention to the millions of people living with this disease. —Steve Pipe, Mercury News, 2 Dec. 2025

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