Sibling - Wikipedia

The word sibling was reintroduced in 1903 in an article in Biometrika, as a translation for the German Geschwister, having not been used since Middle English, specifically 1425.[4][5]

Siblings or full-siblings ([full] sisters or brothers) share the same biological parents. Full-siblings are also the most common type of siblings.[6] Twins are siblings that are born from the same pregnancy.[7] Twins generally share a greater bond due to growing up together and being the same age.

Half-siblings (half-sisters or half-brothers) are people who share one parent. They may share the same mother but different fathers (in which case they are known as uterine siblings or maternal half-siblings), or they may have the same father but different mothers (in which case, they are known as agnate siblings or paternal half-siblings. In law, the term consanguine is used in place of agnate).[citation needed] In law (and especially inheritance law), half-siblings have often been accorded treatment unequal to that of full-siblings. Old English common law at one time incorporated inequalities into the laws of intestate succession, with half-siblings taking only half as much property of their intestate siblings' estates as siblings of full-blood. Unequal treatment of this type has been wholly abolished in England,[8] but still exists in Florida.[9]

Three-quarter siblings share one parent, while the unshared parents are first-degree relatives to each other, for example, if a man has children with two women who are sisters, or a woman has children with a man and his son. In the first case, the children are half-siblings as well as first cousins; in the second, the children are half-siblings as well as a half-avuncular pair. They are genetically closer than half-siblings but less genetically close than full-siblings,[10] a degree of genetic relationship that is rare in humans and little-studied.[11] One notable example of three-quarter siblings is the family of American aviator Charles Lindbergh, who fathered children with two German sisters, Brigitte and Marietta Hesshaimer.

Diblings, a portmanteau of donor sibling, or donor-conceived sibling, or donor-sperm sibling, are biologically connected through donated eggs or sperm.[12][13] Diblings are biologically siblings though not legally for the purposes of family rights and inheritance. The anonymity of donation is seen to add complication to the process of courtship.

Non-blood relations

Related through affinity:

• Stepsiblings (stepbrothers or stepsisters) are the children of one's stepparent from a previous relationship.
• Adoptive siblings are raised by a person who is the adoptive parent of one and the adoptive or biological parent of the other.
• Siblings-in-law are the siblings of one's spouse, the spouse of one's sibling, or the spouse of one's spouse's sibling.[14][15] The spouse of one's spouse's sibling may also be called a co-sibling.[16][17]

Not related:

• Foster siblings are children who are raised in the same foster home: foster children of one's parent(s), or the children or foster children of one's foster parent.[18][19][20]
• God siblings are the children of the godfather or godmother or the godchildren of the father or mother.[citation needed]
• Milk siblings are children who have been nursed by the same woman. This relationship exists in cultures with milk kinship and in Islamic law.[21]
• Cross-siblings are individuals who share one or more half-siblings; if one person has at least one maternal half-sibling and at least one paternal half-sibling, the maternal and paternal half-siblings are cross-siblings to each other.[22][dubious – discuss]