THE MEANING OF THE NAME BARRETT
It must be remembered that it wasn’t until about 1500 that the custom of everyone having one surname only and keeping it was generally established.
Edward McLysaght believes that the Irish Barretts were of two quite distinct families:
The Munster clan (Co Cork) were Barratt (in Irish Baróid); the Connaught Barrett (Co Mayo) (in Irish Bairéid) whereas O’Donovan states that both lines were Welsh.
Woulfe, who writing sixty years later usually accepts O’Donovan’s opinions, disagrees and regards Baróid as of Norman origin (from the Norman French name Baraud), and Bairéad as Anglo-Saxon, meaning quarrelsome or warlike.
Mrs. CM Matthews writes;
As to the nickname Barat or Barate which appears quite often in England in the 12th century and which I still believe is the principal origin of this name, it seems to have been one of those vogue words, popular for a short time and then forgotten. Its period of being “in” just happened to coincide with the most fortunate period of surnames, among the better class. This was a French word and so the name would be found first among Normans whether they went to Ireland or stayed in England. The same goes for the Christian names Beraud or Berard.
In England, of course, they became completely anglicised and the name was spelt in many ways in the middle ages.
 Dan E Barrett, “Barrett News” Issue No. 65, email distribution Feb 20, 2009
 John O’Donovan (1806-1861), Irish scholar and historian
 Patrick Woulfe, Irish Names and Surnames, Dublin, 1923
 Matthews, C.M. English surnames, London, Weidenfeld & Nicolson, 1966