uncharted
adjective literary uk/ʌnˈtʃɑː.tɪd/ us/ʌnˈtʃɑːr.t̬ɪd/
（地方或处境）全新的，未知的，无人涉足的
An uncharted place or situation is completely new and therefore has never been described before.
Nuclear fusion has taken physicists into uncharted seas/territory/waters (= a new and unknown area). 核聚变将物理学家们带入了全新的未知领域。