- (uncommon) One's wife's sister's husband; or more generally one's spouse's brother-in-law, the brother of one spouse in relation to the siblings of the other spouse.
- (uncommon, in the plural) Men who marry sisters.
- (uncommon) One's brother-in-law or sister-in-law's brother; that is, one's sibling's spouse's brother (one's sister's husband's brother or one's brother's wife's brother).
- (in the plural) Men whose brother and sister are married to each other.
- The term is generally used in translation, or in countries such as India (Andhra Pradesh) where the local language makes the distinction. In common speech in traditionally English-speaking countries, brother-in-law may be used.
- The primary usage is for one's wife's sister's husband.
- co- + brother-in-law