Give me 34 types of siblings

Here are 34 different types or categories of siblings, covering biological, legal, cultural, relational and colloquial distinctions:

1. Full sibling — shares both biological parents (same mother and father).
2. Half sibling — shares only one biological parent (same mother or same father).
3. Stepsibling — related by marriage (no biological relation): child of your stepparent.
4. Adoptive sibling — adopted into the same family (legally siblings, not biologically).
5. Foster sibling — children placed in the same foster home (may not be legally related).
6. Blood sibling — informal term emphasizing biological relation (same blood).
7. Uterine sibling (maternal half-sibling) — share the same mother but different fathers.
8. Consanguine sibling (paternal half-sibling) — share the same father but different mothers.
9. Twin sibling — one of two offspring born in the same pregnancy.
10. Identical (monozygotic) twin — twins from one fertilized egg; genetically nearly identical.
11. Fraternal (dizygotic) twin — twins from two eggs; genetically like ordinary siblings but same age.
12. Older sibling — sibling who is older than you.
13. Younger sibling — sibling who is younger than you.
14. Middle sibling — sibling born between older and younger siblings (birth-order category).
15. Only sibling — sole sibling (you have one sibling).
16. Sibling-in-law — spouse of your sibling (brother-/sister-in-law).
17. Half-sibling-in-law — spouse of a half-sibling or half-sibling of a spouse (colloquial use).
18. Step-half sibling — when stepfamily merges and one parent has a child with the other partner (a stepchild who is also a half-sibling by blended-family arrangements).
19. Adopted-out sibling — a biological sibling who was adopted by another family (biologically related but raised elsewhere).
20. Cross-cultural or international sibling — sibling relationship affected by international adoption or migration.
21. Genetic sibling — shares significant DNA (e.g., full or half sibling; used in genetic contexts).
22. Social sibling — considered a sibling by close social relationship though not biologically or legally (e.g., "like a sister/brother").
23. God-sibling — children whose parents are godparents to each other’s children; socially treated like siblings in some cultures.
24. Clan/lineage sibling — related through extended kinship systems where “sibling” includes certain cousins (common in some cultures).
25. Parallel cousin considered sibling — in some kinship systems, a cousin holds the social role of sibling.
26. Sororal sibling — sister (female sibling) specifically.
27. Fraternal sibling — brother (male sibling) specifically.
28. Twinless twin — person whose twin died (in utero, at birth, or later); a unique sibling-loss status.
29. Half-twin (rare/colloquial) — sometimes used when twins have different fathers (heteropaternal superfecundation).
30. Half-sibling by assisted reproduction — e.g., children conceived with the same sperm donor but different mothers (donor half-siblings).
31. Sibling-by-donation — related through egg or sperm donation (donor-conceived sibling).
32. Surrogate sibling — child carried by a surrogate who is genetically related to one of the parents (siblings share parent(s) but gestation differs).
33. Secret/unknown sibling — a sibling unknown to you for part of life (discovered later through family revelations or DNA tests).
34. Donor-conceived donor sibling network member — people who discover they share a gamete donor and form sibling-like networks (often called donor siblings).

Notes:

• Some entries overlap (e.g., donor half-sibling is a type of half sibling). I included legal, biological, social and cultural variants to reach 34 distinct categories.
• Terminology and social meanings vary by culture and legal system; if you want these grouped differently (strictly biological, strictly legal, or by family structure), say which grouping and I’ll reorganize.