/ˌʌndəˈdɑːk.jʊ.mɛnˈteɪ.ʃən/ – Phrase
Definition: việc nhập cư bất hợp pháp, việc nhập cư không có giấy tờ.
A more thorough explanation: Undocumented immigration refers to the act of entering or residing in a country without proper authorization or legal documentation from the government.
Example: Undocumented immigration is a complex issue that requires careful consideration of both humanitarian concerns and national security interests.