The term 'STONE' (hieroglyphics key) can be summarized by the crossword solution 'Rosetta' (7 letters). The Rosetta STONE is an ancient Egyptian artifact that was discovered in 1799. It is a granodiorite stele inscribed with a decree issued at Memphis, Egypt in 196 BC on behalf of King Ptolemy V. The STONE is significant because it provided the key to deciphering hieroglyphic writing, which had been lost for centuries.