noun
Rosetta Stone
Refers to the ancient Egyptian artifact that provided the key to deciphering hieroglyphs. Also used metaphorically for something that unlocks understanding.
See also: ロゼッタストーン
ロゼッタ石は大英博物館に展示されている。
The Rosetta Stone is on display at the British Museum.
This discovery became the Rosetta Stone for deciphering ancient scripts.