TRANSLITERATION. The action, process, or result of converting one set of signs to another, usually involving at least one set of alphabetic letters. Transliteration becomes necessary when two or more writing systems differ greatly. Such differences range along a continuum, from the somewhat similar (ROMAN and Cyrillic), through the significantly dissimilar (Roman ALPHABET, Arabic script), to the utterly different (Roman alphabet, Japanese syllabaries and ideograms). Transliteration became important in the 19c, when European scholars wished to find Roman equivalents for the writing systems of various ‘exotic’ languages. As a result, there are systems of Roman transliteration (each more or less standard for its purposes) for ARABIC, Chinese, GREEK, Japanese, Persian, Russian, SANSKRIT, and Tamil, among others. Conversion to Roman requires, in varying degrees, diacritics and special symbols for sounds or practices that have no equivalent in any prior Roman system.

trans·lit·er·ate / transˈlitəˌrāt; tranz-/ • v. [tr.] (usu. be transliterated) write or print (a letter or word) using the closest corresponding letters of a different alphabet or language: names from one language are often transliterated into another. DERIVATIVES: trans·lit·er·a·tion / transˌlitəˈrāshən; tranz-/ n.trans·lit·er·a·tor / -ˌrātər/ n.

transliterate replace (letters of one language) by those of another for the same sounds. XIX. f. TRANS- + L. littera LETTER + -ATE2.
So transliteration XIX.