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

The jury found Serafini guilty of first-degree murder and attempted murder for the shooting that killed his father-in-law Gary Spohr, 70, and severely wounded his mother-in-law, Wendy Wood, 68, at their home. —Rosalio Ahumada, Sacbee.com, 21 Jan. 2026

Insiders told the outlet the bride believed that her mother-in-law hijacked the nuptials at Montsorrel estate, owned by her parents, billionaire Nelson Peltz and model Claudia Heffner. —Madeleine Marr, Miami Herald, 21 Jan. 2026

The Palisades fire destroyed the Pacific Palisades home of Beutner’s mother-in-law. —David Zahniser, Los Angeles Times, 21 Jan. 2026

Later, she was granted permission to visit her mother-in-law, who had undergone back surgery, in Brevard County. —David Lyons, Sun Sentinel, 20 Jan. 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