noun Jean Fran·çois [zhahn frahn-swa] /ʒɑ̃ frɑ̃ˈswa/, 1790–1832, French Egyptologist. nounJean François (ʒɑ̃ frɑ̃swa). 1790–1832, French Egyptologist, who deciphered the hieroglyphics on the Rosetta stone