What is the etymology of monogram?

1690s, from Fr. monogramme, from L.L. monogramma (5c.), from Late Gk. monogrammon, "a character formed of several letters in one design," especially in ref. to the signature of the Byzantine emperors, from neut. of monogrammos (adj.) "consisting of a single letter," lit. "drawn with single lines," from Gk. monos "single, alone" + gramma "letter, line." Earlier it meant "sketch or picture drawn in lines only, without shading or color," a sense also found in Latin and probably in Greek. Related: Monogrammed.