By Brythonic I meant all languages of the British Isles (Ireland, England...). That would include Gaelic - Irish, Welsh, Scottish, etc. I guess Brythonic might be misleading if regarded strictly as the southern grouping of Celtic languages, however 
www.dictionary.com  yields the definition of Brythonic I was referring to.
"Brit·ton·ic    ( P )  Pronunciation Key  (br-tnk) also Bry·thon·ic (-thn-)
n. 
The subdivision of the Insular Celtic languages that includes Welsh, Breton, and Cornish.
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[Ultimately from Latin Brittons, Britons. See Briton.] 
Source: The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2000 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Bry·thon·ic    ( P )  Pronunciation Key  (br-thnk)
adj. 
Of or relating to the Brythons or their language or culture.
n. 
Variant of Brittonic. 
Source: The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2000 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved."
So I think I'm covered. [img]smilies/smile.gif[/img]