/rɪˈtɛnʃən ʌv ˌnæʃəˈnælɪti/ – Phrase
Definition: bảo lưu quốc tịch cũ, giữ lại quốc tịch cũ.
A more thorough explanation: Retention of nationality refers to the legal concept where an individual is allowed to maintain their citizenship or nationality of a particular country even after acquiring the citizenship of another country. This means that the individual does not lose their original nationality when they become a citizen of another country.
Example: The retention of nationality clause in the immigration law allows individuals to maintain their original citizenship even after acquiring a new one.