Linguist (b. 1895, İstanbul – d. 1979). His original name was Agop Dilaçar Martayan. He completed his primary education at an American school that was opened by missionaries in Gedikpaşa. He graduated from Robert College (1915). He learned English, Greek, Spanish, Latin, German, Russian and Bulgarian and worked in jobs using these languages. He gave English lectures at Robert College and ancient East and Ottoman language lectures at Suaboden University in Sofia.
His articles were published in Armenian newspapers published in Europe and İstanbul. He was invited to the First Turkish Language Congress by Atatürk and appointed as the Head Specialist of the Turkish Language Association (1934). He was given the surname Dilaçar (1935). He worked as a teacher of language history at Ankara University, Ankara University, Faculty of Language, History and Geography (1936- 51) and head advisor at the Türk Ansiklopedisi (Turkish Encyclopedia, 1942- 60). He continued his studies and research on language and his office as the Secretary General of the Turkish Language Association until his death.
Azeri Türkçesi (Azerbaijan Turkish, 1950), Batı Türkçesi (Western Turkish, 1953), Lehçelerin Yazılma Tarzı (Writing Style of Dialects), Türk Dil ve Lehçelerinin Tasnifi Meselesi (Classification Issue of the Turkish Languages and Dialects, 1954), Devlet Dili Olarak Türkçe (Turkish as a State Language, 1962), Wilhelm Thomsen ve Orhon Yazıtlarının Çözülüşü (Wilhelm Thomson and Encoding of the Orhon Inscriptions, 1963), Türk Diline Genel Bir Bakış (A General Look at the Turkish Language, 1964), Türkiye'de Dil Özleşmesi (Language Purification in Turkey, 1965), Dil, Diller ve Dilcilik (Language, Languages and Linguistic, 1968), Kutadgu Bilig İncelemesi (Research of the Kutadgu Bilig, 1972), Anadili İlkeleri ve Türkiye Dışındaki Uygulamalar (Native Language Principles and Applications Outside Turkey, 1978).