___ Stone (relic inscribed in three languages)

ROSETTA

This famous artifact was discovered in Egypt in 1799 and helped scholars finally decipher ancient Egyptian hieroglyphs by comparing them to known Greek text.

This clue refers to the famous Rosetta Stone, an ancient artifact discovered in 1799 that contains the same text carved in three scripts: Greek, Demotic, and hieroglyphics. The blank in the clue hints at the missing first word of its name, and "inscribed in three languages" directly points to its historical significance in deciphering Egyptian hieroglyphs. Since the answer is a single word, "ROSETTA" fits perfectly as the well-known name tied to this relic.