Definition - What does Posthumous Child mean?
A posthumous child is one that is born after their father dies, but whose gestation period can definitely show that the child could be the issue of the deceased parent. In this scenario, the posthumous child would inherit as a beneficiary in the same way as if they were already born.
Justipedia explains Posthumous Child
A trust can be established for a posthumous child that retains their inheritance for their benefit until they reach a certain age. It can also be used by the guardian of the child for the purpose of raising the child if needed.