mother-in-law

[muhth-er-in-law]

noun

plural

mothers-in-law 

1. the mother of one's spouse.

mother-in-law

noun

1. the mother of one's wife or husband

Word History and Origins

Origin of mother-in-law¹

First recorded in 1350–1400; Middle English moder in lawe; mother ¹ ( def. ), in ( def. ), law ¹ ( def. ); from Middle English in-lawe “in law,” i.e., “a person within the regulation and protection of the law,” based on the prohibition by Roman civil law and, later, Christian canon law, of marriages within four degrees of consanguinity, i.e., up to and including first cousins

Example Sentences

Angela left behind her mother, her older brother, and her mother-in-law, who refused to leave the home.

Read more on Barron's

‘She lives alone’: My mother-in-law, 86, gets $1,300 in Social Security.

Read more on MarketWatch

He said his mother-in-law grew up in Nazi Germany and watched as the synagogue across the street from her home was burned to the ground.

Read more on The Wall Street Journal

His mother-in-law, whose Altadena home survived the fire, wears a mask when gardening in the backyard.

Read more on Los Angeles Times

For months, Indonesian movie audiences have been talking about one film: Norma, the story of a seemingly blissful marriage shattered by the husband's clandestine affair with his mother-in-law.

Read more on BBC

Related Words

• aunt 
• cousin 
• father 
• folk 
• mother 
• niece 
• sibling 
• uncle