undocumented
adjective uk/ʌnˈdɒk.jə.men.tɪd/ us/ʌnˈdɑː.kjə.men.t̬ɪd/
(WITHOUT PROOF)
没有书面证明支持的
not supported by written proof
People should not stop eating fish because of some undocumented risk of cancer. 人们不应该一些并无书面证据支持的致癌风险而不再吃鱼了。
(WITHOUT DOCUMENTS)
没有（在一个国家生活或工作的）合法身份文件的
not having any documents to prove that you are living or working in a country legally
undocumented immigrants/aliens/workers 没有合法文件的移民／外国人／工人