naturalization

US /ˌnætʃ.ɚ.rə.ləˈzeɪ.ʃən/
UK /ˌnætʃ.ɚ.rə.ləˈzeɪ.ʃən/
"naturalization" picture
1.

the process by which an immigrant becomes a citizen of a new country

:
The ceremony for naturalization was held last week.
He completed all the requirements for naturalization.