noun
ancient times; remote antiquity
Refers to very old times, often in historical or literary contexts. In Japanese history, it can specifically denote the Jōko period (ancient era).
上古の遺跡から貴重な土器が出土した。
Valuable pottery was excavated from ancient ruins.
この風習は上古にまでさかのぼる。
This custom dates back to ancient times.