There have been several etymologies proposed for the term Persian.  Here are the mainstream trends in scholarship.

There have in fact been several proposals concerning the etymology of the term “Parsa“.  In Hoffman’s view (1940: 142) the name is related to Old Indian Parsu-, the name of a warrior tribe.  Eilers (1954: 188: also Harmatta 1971c: 221-222) uses Assyrian Parsua to prove Parsa — evolved from *Parsva-.  Eilers (1987:49) however finds yet another Old Indian word to explain Parsa.  This time it is “Parsu“-, “rib, sickle”.  More recently Skalmowski (1995:311) indicated that Pars(u)a is the equivalent of Old Indian Parsva, “the region of the ribs, immediate neighborhood”.

The eminent Iranologist George Morgenstriene has shown that Parsa, Pahlu, Pashtu, Parthia and etc. are all cognates of the same word. 

The actual term Persian has been used for various Iranian groups and in the Islamic time, it generally meant Iranian.

Here are some examples:

A) Arabic sources. The Arabian historian Abu al-Hasan Ali ibn al-Husayn Al-Masudi (896-956) also refers to various Persian dialects and the speakers of these various Persian dialects as Persian.  While considering modern Persian (Dari) to be one of these dialects, he also mentions Pahlavi and Old Azari (An Iranian dialect of Azerbaijan before its linguistic Turkification and probably Talyshi is a modern descendant of that language), , as well as other Persian languages. Al-Masudi states:(Al Mas’udi, Kitab al-Tanbih wa-l-Ishraf, De Goeje, M.J. (ed.), Leiden, Brill, 1894, pp. 77-8). 

Original Arabic from www.alwaraq.net: فالفرس أمة حد بلادها الجبال من الماهات وغيرها وآذربيجان إلى ما يلي بلاد أرمينية وأران والبيلقان إلى دربند وهو الباب والأبواب والري وطبرستن والمسقط والشابران وجرجان وابرشهر، وهي نيسابور، وهراة ومرو وغير ذلك من بلاد خراسان وسجستان وكرمان وفارس والأهواز، وما اتصل بذلك من أرض الأعاجم في هذا الوقت وكل هذه البلاد كانت مملكة واحدة ملكها ملك واحد ولسانها واحد، إلا أنهم كانوا يتباينون في شيء يسير من اللغات وذلك أن اللغة إنما تكون واحدة بأن تكون حروفها التي تكتب واحدة وتأليف حروفها تأليف واحد، وإن اختلفت بعد ذلك في سائر الأشياء الأخر كالفهلوية والدرية والآذرية وغيرها من لغات الفرس.”

Translation:

The Persians are a people whose borders are the Mahat Mountains and Azarbaijan up to Armenia and Arran, and Bayleqan and Darband, and Ray and Tabaristan and Masqat and Shabaran and Jorjan and Abarshahr, and that is Nishabur, and Herat and Marv and other places in land of Khorasan, and Sejistan and Kerman and Fars and Ahvaz…All these lands were once one kingdom with one sovereign and one language…although the language differed slightly.  The language, however, is one, in that its letters are written the same way and used the same way in composition.  There are, then, different languages such as Pahlavi, Dari, Azari, as well as other Persian languages.

B) Khwarezmian language (an East Iranian language which is a close relative to the Avesta).  For example, Abu Rayhan Biruni, a native speaker of the Eastern Iranian language Chorasmian mentions in his ”Āthār al-bāqiyah ʻan al-qurūn al-xāliyah” that: “the people of Khwarizm, they are a branch of the Persian tree.”

Original Arabic of the quote: “و أما أهل خوارزم، و إن کانوا غصنا ً من دوحة الفُرس”(pg 56)

C)  Old  Tabari language.   According to the Encyclopedia of Islam, the language used in the ancient Marzbannama (an important book of literature) was, in the words of the 13th-century historian and translator Sa’ad ad-Din Warawini: ” the language of Ṭabaristan and old, original Persian (fārsī-yi ḳadīm-i bāstān’)”.  That is Sa’ad ad-Din Warawini has called the old Iranic dialect of Tabari as Old Persian. Kindly consult Kramers in references.

D) Ancient Iranic language of Tabriz. The old Iranic language of Tabriz (Tabriz became predominantly Turcophone only after the mass conversion of the city from Shafii Sunnism to 12 Imam Shi’ism in the Safavid era) , being an Iranian language during the time of Qatran Tabrizi (10th century poet of Azarbaijan), was not the standard Khurasani Parsi-ye Dari.  Qatran Tabrizi(11th century) has an interesting couplet mentioning this fact.

 

بلبل به سان مطرب بیدل فراز گل

گه پارسی نوازد، گاهی زند دری

Translation:

The nightingale is on top of the flower like a minstrel who has lost her heart

It bemoans sometimes in Parsi (Persian) and sometimes in Dari (Khurasani Persian)

 

Consult Riahi in references below for further information. 

E) Laki language and Kurdish language speakers. Lady (Mary) Shiel in her observation of Persia during the Qajar era describes the Persian tribes and Koords/Laks identified themselves and were identified commonly as Old Persians.  See: Shiel, Lady (Mary). Glimpses of Life and Manners in Persia. London: John Murray, 1856.

(see pg 394)

Quote:

“The PERSIAN TRIBES. The tribes are divided into three races-Toorks, Leks, Arabs.  The first are the invaders from Toorkistan, who, from time immemorial, have established themselves in Persia, and who still preserve their language. The Leks form the clans of genuine Persian blood, such as the Loors, BekhtiaTees, and &c.. To them might be added the Koords, as members of the Persian family; but their numbers in the dominions of the Shah are comparatively few, the greater part of that widely-spread people being attached to Turkey. Collectively the Koords are so numerous that they might be regarded as a nation divided into distinct tribes. Who are the Leks, and who are the Koords? This inquiry I cannot solve. I never met any one in Persia, either eel (means tribe) or moolla (means religious scholar), who could give the least elucidation of this question. All they could say was, that both these races were Foors e kadeem, — old Persians. They both speak dialects the greater part of which is Persian, bearing a strong resemblance to the colloquial language of the present day, divested of its large Arabic mixture. These dialects are not perfectly alike, though it is said that Leks and Koords are able to comprehend each other. One would be disposed to consider them as belonging to the same stock, did they not both disavow the connection. A Lek will- admit that a Koord, like himself, is an “old Persian,” but he denies that the families are identical, and a Koord views the question in the same light. (Murray, 1896, pp.394)

link: http://books.google.com/books/download/Glimpses_of_life_and_manners_in_Persia.pdf?id=zYZi0qSfHxoC&output=pdf&sig=ACfU3U2FxSM4IPAmAqXqmugwotcL6C8JpQ&source=gbs_v2_summary_r&cad=0

F) Ibn Battuta, visiting Kabul in 1333 writes: “We travelled to Kabul, formerly a vast town, the site of which Is now occupied by a tribe of Persians called Afghans”

Nancy Hatch Dupree at American University of Afghanistan – The Story of Kabul (Mongols

http://www.aisk.org/aisk/NHDAHGTK05.php#Top

Thus the term was used by travelers for Pashtuns who are a major Iranian ethno-linguistic group The term therefore designated Iranian speakers during the Islamic era.

Further Readings

Kramers, J.H. “Marzban-nāma.” Encyclopaedia of Islam. Edited by: P. Bearman , Th. Bianquis , C.E. Bosworth , E. van Donzel and W.P. Heinrichs. Brill, 2007. Brill Online.  18 November 2007 <http://www.brillonline.nl/subscriber/entry?entry=islam_SIM-4990>;

Morgenstriene, George (1973).: ‘Pashto’, ‘Pathan’ and the treatment of R + sibilant in Pashto,in: Indo-Dardica, Wiesbaden: Reichert, 168-174.

Tavernier, Jan. (2007). “Iranica in the Achamenid Period (c.a. 550-330 B.C.); lexicon of old Iranian proper names and loanwords, attested in non-Iranian texts.  Volume 158 of Orientalia Lovaniensia Analecta.  Peeters Publisher, 2007.  Pg 28

Riahi, Mohammad-Amin .  “Molehaazi darbaareyeh Zabaan-I Kohan Azerbaijan”(Some comments on the ancient language of Azerbaijan), ‘Itilia’at Siyasi Magazine, volume 181-182. Also available at:

http://web.archive.org/web/*/http://www.azargoshnasp.net/languages/Azari/26.pdf

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