uncharted

1. ADJ If you describe a situation, experience, or activity as uncharted territory or waters, you mean that it is new or unfamiliar. (情形、经历、活动)不为人熟悉的; (地域、水域)未被探索的[usu ADJ n]

Carter's fourth album definitely moves into uncharted territory. 卡特的第四张专辑绝对进入了一个未被探索过的领域。