father-in-law

UK: ˈfɑːðər ɪn lɔː | US: ˈfɑðər ɪn lɔː

Definition

  1. n. the father of one’s spouse

Structure
father <male parent>in <within/related by marriage>law <legal bond>
Etymology

The term "father-in-law" combines three morphemes:

  1. "Father" (Old English fæder), meaning a male parent.
  2. "In" (Old English in), here denoting a relational connection through marriage.
  3. "Law" (Old English lagu), originally meaning "bond" or "custom," later evolving to signify legal ties.
    The phrase emerged in Middle English to describe familial relationships formalized by marriage, reflecting societal emphasis on legal kinship structures. Unlike biological terms, "-in-law" marks affinity rather than consanguinity.
Examples

  1. My father-in-law taught me how to fish last summer.

  2. She has a close relationship with her father-in-law.

  3. He invited his father-in-law to the business meeting.

  4. In some cultures, the father-in-law plays a key role in family decisions.

  5. They celebrated their father-in-law’s birthday with a surprise party.