The paper is going to study the methods of determination of the homonymous and polysemous entries in Persian to Persian monolingual dictionaries such as Dehkhoda Dictionary (Loghatname-ye-Dehkhoda), Amid Dictionary (Farhang-e-Amid), Dictionary of Contemporary Persian (Farhange Farsi-ye-Emrooz), Sokhan Dictionary (Farhange Bozorge Sokhan) and Persian to English Dictionaries including Aryanpour Progressive Dictionary (Farhenge Pishro Aryanpour) and English to English dictionaries such as: Longman Dictionary of Contemporary English, Oxford Advanced Learner’s Dictionary, Webster’s New Collegiate Dictionary, and American Heritage Dictionary. For this reason the present paper has been divided into several sections. In the first section some basic terms and concepts that are related to meaning determination and meaning separation are defined, then in the next sections the subject of meaning separation of the above mentioned dictionaries are studied.At first from each dictionary some homonymous entries are chosen, then the method of determination of meaning and separation of meaning in each of them is discussed and studied. Since in Persian and English dictionaries the entries that are not homonymous make no problems, in the present study these entries are nit included, and only homonymous entries and with multiple meanings in Persian to Persian, Persian to English, and English to English dictionaries are concerned, and the authors would like to study the methods in each group of dictionaries by comparison of the separation of the meaning of the headwords.