Orphan:

A child who has no parents because of death, disappearance, desertion or abandonment of the parents.  A child may also be considered an orphan if the child has an unwed mother, or a single living parent who cannot care for the child and has released him/her irrevocably (permanently) for adoption and emigration.  Adoptive parents must make sure that a child meets the legal definition of an “orphan” before adopting a child from another country.