lexicography, the applied study of the meaning, evolution, and function of the vocabulary units of a language for the purpose of compilation in book form—in short, the process of dictionary making. Early lexicography, practiced from the 7th cent. B.C. in Mesopotamia, Greece, and Rome, was reserved for abstruse words of specific disciplines. General lexicography originated in the 16th cent., and aspects of the modern dictionary, such as etymology, developed during the 17th and 18th cent.