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Definition of "mother-in-law" [moth•er-in-law]

  • The mother of one's wife or husband. (noun)
  • Archaic A stepmother. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Use "mother-in-law" in a sentence
  • "Home builders across the country say they are getting an increasing number of requests for such additions, known as mother-in-law suites, granny flats or accessory dwellings."
  • "Lucrezia often referred to her mother-in-law as Saint Contessina as a result."
  • "Because of the time difference their celebrations would already be under way, so after calling her mother at her retirement community in Erie, Bonnie planned to call her mother-in-law in Scranton, where her children and grandchildren were attending the traditional family gathering."