Adoption

noun

1. The act of adopting.
2. The state of being adopted; the acceptance of a child of other parents as if he or she were one's own child.

   "A Chinese baby girl was given away for adoption."

3. Admission to an institution, for example a hospital, clinic, mental asylum.

   "the adoption of people into hospitals or monasteries"

4. The choosing and making that to be one's own which originally was not so; acceptance

   "the adoption of opinions"

5. Transfer between an old system to another (usually better) system.

   "Our company is considering the adoption of a four-day week."