uncharted
/ˌʌnˈtʃɑːtɪd/adjective
- (of an area of land or sea) not mapped or surveyed（地区或海洋）地图未标明的; 未经探测的。
USAGE
Uncharted means 'not yet mapped or surveyed'. Especially in the phrase uncharted territory, it is confused with unchartered, a far less common word that means 'not having a charter or written constitution'. Unchartered territory constitutes around 10 per cent of the total citations for the phrase in the Oxford English Corpus.