father-in-law
Americannoun
plural
fathers-in-lawnoun
Etymology
Origin of father-in-law
First recorded in 1350–1400; Middle English fader in lawe; father, in, law 1; 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
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Ryu, whose father-in-law is still part of Kim Jong Un's inner circle, says the debate around Kim's heir may be a goal in itself.
From BBC • Mar. 1, 2026
Warsh’s father-in-law is Ron Lauder, a longtime friend of Trump’s.
From Barron's • Jan. 30, 2026
“It has become increasingly difficult to meet the price points expected by American buyers,” said Agnieszka Chmielewska, whose husband and father-in-law run the company.
From The Wall Street Journal • Jan. 28, 2026
His father-in-law, billionaire businessman Ronald Lauder, is a longtime Trump donor and ally.
From BBC • Dec. 23, 2025
In the case of Grant, his enslaved people were given to his wife by his father-in-law.
From "In the Shadow of Liberty" by Kenneth C. Davis
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
