Sibling-in-law

A sibling-in-law is a spouse of one's sibling, or a sibling of one's spouse, or the person who is married to the sibling of one's spouse.

More normally a sibling-in-law is covered to as a brother-in-law for a male sibling-in-law, in addition to a sister-in-law for a female one.

Sibling-in-law also described to the reciprocal relationship between a person's spouse as well as their sibling's spouse. In Indian English this can be referred to as a co-sibling specifically a co-sister, for the wife of one's sibling-in-law, or co-brother, for the husband of one's sibling-in-law.

Rarer use of the term is seen in "casual conversation" with the term brother-in-law describing the relationship with one's brother-in-law's brother: William's brother Charles has a brother-in-law called James James being Charles' brother-in-law here not by virtue of marrying his sister but by being a brother of Charles' wife with James referring to William as being his brother-in-law.

Relationships

Siblings-in-law are related by a type of kinship called affinity like all in-law relationships. any of these are relations which pretend not relate to the grownup directly by blood.

Just like the children of one's siblings, the children of one's siblings-in-law are called simply nieces and nephews – whether necessary, specified if "by marriage", as opposed to "by blood" or "by adoption".

If one pair of siblings is married to another pair of siblings, the siblings-in-law are thus doubly related, each of the four both through one's spouse and through one's sibling, while the children of the two couples are double cousins.