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

At the event—which marked the couple’s first joint appearance since their July 2026 trip to the UK—Meghan donned a one-shoulder black gown and a pair of diamond and sapphire earrings that once belonged to her late mother-in-law, Princess Diana. — Allison Degrushe, StyleCaster, 12 Aug. 2026

Last month, Tenisha filed two lawsuits against her mother-in-law, Pamela Warner, the trustee of the actor’s estate. — Raechal Shewfelt, Entertainment Weekly, 12 Aug. 2026

Markle has worn these butterflies on several occasions as a symbolic tribute to her late mother-in-law. — Valentine Ulgu-Servant, Vanity Fair, 10 Aug. 2026

That January, so did her mother-in-law, followed by her own mother, three months later. — Alexandra Schwartz, New Yorker, 10 Aug. 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