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

For me, that’s my mother-in-law’s brownie trifle. —Melinda Salchert, Southern Living, 2 Mar. 2026

Meanwhile, Derek’s mother-in-law visits, and Paul ponders his legacy. —Jessica Radloff, Glamour, 1 Mar. 2026

Former Major League Baseball pitcher Dan Serafini was sentenced to life in prison without the possibility of parole Friday for the 2021 first-degree murder of his father-in-law and attempted murder of his mother-in-law in Lake Tahoe. —Steve Henson, Los Angeles Times, 28 Feb. 2026

Serafini, 51, was convicted in July 2025 of first-degree murder of his father-in-law, Gary Spohr, attempted murder of his mother-in-law, Wendy Wood, and first-degree burglary. —Jessica Hill, Chicago Tribune, 28 Feb. 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