brother-in-law
UK: ˈbrʌðər ɪn lɔː | US: ˈbrʌðər ɪn lɔː
n. the brother of one's spouse
n. the husband of one's sibling
n. the husband of one's spouse's sibling
The term "brother-in-law" combines "brother" (Old English brōþor) with the phrase "in law," which historically denoted relationships formed through marriage rather than blood. The "in law" component originates from Old English lagu (law), reflecting the legal or contractual nature of such kinship ties. Over time, the phrase solidified into a compound noun to describe specific marital relations.
My brother-in-law helped me move into the new apartment.
She invited her brother-in-law to the family reunion.
His brother-in-law is a doctor at the local hospital.
We celebrated Thanksgiving with my sister and her brother-in-law.
The wedding photo included the groom’s brother-in-law.