You searched for: “naturalization
naturalization (s) (noun), naturalizations (pl)
1. The process of granting citizenship: The application for naturalisation was to be completed along with all the necessary documents before being presented to the officials.
2. The means of becoming or the condition of a living thing being successfully introduced into the wild, including growth and development: If an otherwise non-native plant is put into a new environment, and it thrives without human help, the naturalisation process begins.