In Francis Buchanan – A Comparative Vocabulary of the Languages spoken in Burma Empire – Page 223 does not support the claims made by some researches which then becomes fact by Journalist. I am concerned that page 237 is the corner stone of this historical discourse. You do not let your reader know that ‘the proper natives call themselves Yakain.’ Buchanan goes on to state the “Bengal Hindus … have been settled in Arakan, the country is called Roffawn ….. not conceiving that it would be Arakan. Buchan goes on to say in the same page at the very bottom “The Mohommedans settled at Arakan call the country Rovingaw.”
Yes, on page 237 there is a one mention of Rooingo. Buchanan goes on to say that Hindus of Arakan wanted to persuade him that theirs was the common language of Arakan , ‘for what reason I do not know.’ There is no analysis on this claim. Francis Buchanan mentioned “Rooinga” a single time only, never appeared again in any of his writings. It should had been appeared many times if “Rooinga” is an ethnic or race name at that time.
As well, according to Jacques Leider, the word “Rohingya” (under the form “Rooinga”) appears a single time in a pre-colonial English text (BUCHANAN, Francis 1799. “A comparative vocabulary of some of the languages spoken in the Burma Empire” Asiatick Researches or Transactions of the Society instituted in Bengal for inquiring into the History and Antiquities the Arts, Sciences and Literature of Asia, volume V, p. 219-240.). You also can find it at below link (page 3 – 5):

I take this analysis from Dr. Leider’s views:
“Dr. Francis Buchanan-Hamilton used the term “Rooinga” in a paper written in 1798 describing languages spoken in the “Birman Empire”. How should one interpret the fact that the term “Rooinga” appears a single time in an English language document before 1951 and never in any British colonial administrative text or census during the whole colonial period, i.e. 1826-1948?
The Muslims that Hamilton met in Amarapura in 1795 had been deported from Arakan, conquered in 1785 by the Burmese king. They referred to themselves in their own language as “Arakanese”, because the term “Rooinga”/ spelt “Roewhengya” by Ba Tha, the chief Rohingya “historian” and creator of the myth of a unified Rohingya race / now spelt: Rohingya, is derived from Rakhanga and means nothing more than Arakanese. Many fancy etymologies are circulating to explain the word, and often they tend to discard the obvious connection with Roshang or Rohang as found in Bengali sources since the 17th c.
It is is rather clear from contextual source evidence that the term heard by Hamilton was not used in the modern sense of a separate ethnic group of Muslims.
First of all, Hamilton was the best expert on Southeast Bengal and never used the term while talking about people in the region. He traveled in the Chittagong District and noted any ethnic group that he met during his travels and he specifically also mentions Muslims who had fled from Arakan after 1785 to Chittagong. Still he did not call them Rohingyas nor did they call themselves “Rooinga” because they were Muslims who integrated themselves into the local Muslim society where their forefathers had come from. Hamilton also wrote three detailed articles on the Bengal-Arakan frontier after his retirement and never mentions any distinctive ethnic group called such.
Second, no British administrative document during the colonial period mentions a separate ethnic group that referred to itself or was referred to by others as Rohingyas. This is not because the British census makers were still confused about the profile of Muslims in Arakan after 50 or 60 years of domination. They made indeed, as one sees in the 1931 census for example, a clear difference between recent migrants (called Chittagonians, to specify their origins in Bengal) and the old stock of the Muslim community referred to as Arakan Muhammedans. The old community formed then a sixth of the total of 300,000 in Akyab district.
Third, no early 19th century Western source on Arakan that mentions the Muslims, ever uses the term “Rohingya”. Muslims are each time described as being assimilated to the local Buddhist population in their living style, with the sole exception of their religion.”