In standard English, your wife’s sister’s husband can be called your “brother-in-law.” Because that term covers several different family relationships, a descriptive phrase is often clearer. Indian English also has more specific terms such as “co-brother.”
Terms From General to Most Specific
- Brother-in-law
- My wife’s brother-in-law
- My sister-in-law’s husband
- The husband of my wife’s sister
- My wife’s sister’s husband
- A sibling-in-law
- Co-brother
- Co-brother-in-law
Brother-in-law
The standard broad English term; it can refer to several male in-law relationships, including the husband of your spouse’s sibling.
Example: My brother-in-law is married to my wife’s younger sister.
My wife’s brother-in-law
A clear relational phrase, though listeners may still need context because “brother-in-law” itself is broad.
Example: My wife’s brother-in-law joined us for dinner.
My sister-in-law’s husband
Often the clearest everyday description when the sister-in-law relationship is already understood.
Example: My sister-in-law’s husband works in Manchester.
The husband of my wife’s sister
Unambiguous standard English when precision matters more than brevity.
Example: The husband of my wife’s sister is coming to the wedding.
My wife’s sister’s husband
The most literal description of the relationship and completely unambiguous.
Example: My wife’s sister’s husband helped us move house.
A sibling-in-law
A technical umbrella term for several relationships involving a spouse or sibling; it is accurate but uncommon in everyday conversation.
Example: Technically, he is a sibling-in-law, though I normally say brother-in-law.
Co-brother
An established Indian English term specifically used for the husband of one’s wife’s sister.
Example: In Indian English, Raj may refer to his wife’s sister’s husband as his co-brother.
Co-brother-in-law
An uncommon extended term used for the same relationship; most speakers of British or American English would simply say “brother-in-law.”
Example: The family tree labels the two men as co-brothers-in-law.
Which Term for “Your Wife’s Sister’s Husband” Is Most Natural?
In ordinary British and American English, “brother-in-law” is the natural choice, even though it is ambiguous. Use “my wife’s sister’s husband” or “my sister-in-law’s husband” when the exact relationship needs to be unmistakable.