father-in-law
UK[ˈfɑːðər ɪn lɔː]US[ˈfɑðər ɪn lɔː]
n
the father of a person's husband or wife
Morpheme Breakdown
father
in
law
father
in
law
something laid down or fixed.
Etymology
The term is a compound noun originating in Middle English, directly combining the native English words 'father', 'in', and 'law'. It reflects a societal and legal construct where marriage creates binding kinship ties, metaphorically placing the spouse's parent "in the realm of law" rather than blood. The preposition 'in' here signifies a relationship constituted by legal and customary bonds. Thus, the term literally means "a father by legal affiliation," distinguishing this relationship from a biological father.
Analysis
Structure: father + in + law
- father: From Old English fæder, from Proto-Germanic fadēr, from Proto-Indo-European ph₂tḗr. Functions as the core noun denoting a male parent.
- in: From Old English in, a preposition indicating a state or condition.
- law: From Old English lagu, from Old Norse lag, meaning "something laid down or fixed." In this compound, it functions to denote a relationship defined by custom or legal statute.
Examples
He gets along very well with his father-in-law.
We are going to visit my father-in-law for the holidays.
Her father-in-law helped them with the down payment on their first house.