Merriam-Webster Collegiate Dictionary - hieroglyphic

 I. adjective  also ~al  Etymology: Middle French hieroglyphique, from Late Latin ~us, from Greek hieroglyphikos, from hieros + glyphein to carve — more at cleave  Date: 1585  1. written in, constituting, or belonging to a system of writing mainly in pictorial characters  2. inscribed with ~  3. resembling ~ in difficulty of decipherment  • ~ally adverb  II. noun  Date: 1586  1. hieroglyph  2. a system of ~ writing; specifically the picture script of the ancient Egyptian priesthood — often used in plural but sing. or plural in constr.  3. something that resembles a hieroglyph especially in difficulty of decipherment