A child, conceived by selected IVF treatment, so as to have compatible tissue that could be used to treat an existing sick brother or sister

A person who shares the same set of biological parents

A person who is not one's biological sibling, but was legally and socially raised as if they were.

The sibling of one's spouse. / The spouse of one's sibling. / The spouse of the sibling of one's spouse. / The sibling of the spouse of one's sibling.

Alternative spelling of half sibling

A half sibling having the same mother but a different father.

(vulgar) Motherfucker (generic term of abuse). / (literally, vulgar) One who engages in incestuous sex with their sibling.

plural of sibling fucker

A sibling sharing a single parent, as distinguished from a full sibling or sibling-german, from a step-sibling, or from a sibling-like figure such as a blood sibling.

Alternative form of full-sibling