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Definitions

father-in-law

[fah-ther-in-law] / ˈfɑ ðər ɪnˌlɔ /
NOUN
kinsman
Synonyms
STRONG
agnate aunt blood brother-in-law cognate connection cousin father folk folks grandparents in-laws kin kinsperson kinswoman mother mother-in-law nephew niece relation sib sibling sister-in-law stepbrother stepparent stepsister uncle
WEAK
clansperson great-grandparents
NOUN
kinswoman
Synonyms
STRONG
agnate aunt blood brother-in-law cognate connection cousin father folk folks grandparents in-laws kin kinsman kinsperson mother mother-in-law nephew niece relation sib sibling sister-in-law stepbrother stepparent stepsister uncle
WEAK
clansperson great-grandparents
NOUN
relative
Synonyms
STRONGEST
aunt cousin father folk mother niece sibling uncle
STRONG
agnate blood brother-in-law cognate connection folks grandparents in-laws kinsperson mother-in-law nephew relation sib sister-in-law stepbrother stepparent stepsister
WEAK
clansperson great-grandparents

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.

Police filed a criminal charge against the father-in-law, though it was later dismissed.

From BBC • Feb. 17, 2026

At Materiales El Valle, a local tile supplier, the ICE crackdown has resulted in $5.3 million in lost sales, said Luis Rodriguez, who manages the company his father-in-law started four decades ago.

From The Wall Street Journal • Feb. 9, 2026

Warsh’s father-in-law is Ron Lauder, a longtime friend of Trump’s.

From Barron's • Jan. 30, 2026

His father-in-law, billionaire businessman Ronald Lauder, is a longtime Trump donor and ally.

From BBC • Dec. 23, 2025

My mother never said she didn’t like her father-in-law, but I could tell she didn’t, and that may of been why.

From "Cold Sassy Tree" by Olive Ann Burns