Written by Dehkhoda during thirty-five years of continuous work. The last chapter of Loghat Nameh’s first edition was published in 1981, fifty years after its first chapter. The entire series consisted of 222 chapters that took 26000 pages. The chapters included 342262 topics and 57547 expressions with documented references to the Persian literary texts. Whereas Loghat Nameh Dehkhoda is not an encyclopedia by definition, it contains lots of reference articles on various subjects. After Dehkhoda’s death the Iranian Parliament took over his work and in 1957 it entrusted the Department of Persian Language and Literature of the University of Tehran with the supervision over Loghat Nameh Dehkhoda. Dr. Mohammad Moin, a well-known university professor who had co-authored Dehkhoda in his work over Loghat Nameh, was appointed Chairman of the LoghatNameh Dehkhoda Institute, while. Dr. Jafar Shahidi, a distinguished academician, was chosen Vice Chairman. Since Dr. Moin’s death in 1971, Dr.Shahidi has headed the Loghat Nameh Dehkhoda Institute. He also presides the International Institute ofthe Persian Language. For details on the history of the Loghat Nameh Dehkhoda Institute, please refer to the introductory chapter of Loghat Nameh Dehkhoda.