rosetta stone

from WordNet (r) 3.0 (2006)

Rosetta Stone
    n 1: a part of an inscribed granite stela that was originally
         about six feet tall and was set up in 196 BC; the
         inscriptions in hieroglyphics and Demotic and Greek gave
         the first clues to the decipherment of Egyptian
         hieroglyphics

from The Collaborative International Dictionary of English v.0.48

Ro-setta stone \Ro-set"ta stone`\
   A stone found at Rosetta, in Egypt, bearing a trilingual
   inscription, by aid of which, with other inscriptions, a key
   was obtained to the hieroglyphics of ancient Egypt. --Brande
   & C.
   [1913 Webster]

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