New American Oxford Dictionary
Brythonic
Bry thon ic |briˈTHänik brɪˈθɑːnɪk |(also Brittonic |briˈtänik |) ▶adjective denoting, relating to, or belonging to the southern group of Celtic languages, consisting of Welsh, Cornish, and Breton. Compare with Goidelic. Also called P-Celtic. ▶noun these languages collectively. ORIGIN from Welsh Brython ‘Britons ’ + -ic .
Oxford Dictionary
Brythonic
Brythonic |brɪˈθɒnɪk |(also Brittonic ) ▶adjective denoting or relating to the southern group of Celtic languages, consisting of Welsh, Cornish, and Breton. They were spoken in Britain before and during the Roman occupation, surviving as Welsh and Cornish after the Anglo-Saxon invasions, and being taken to Brittany by emigrants. Compare with Goidelic. Also called P-Celtic. ▶noun [ mass noun ] the Brythonic languages collectively. ORIGIN from Welsh Brython ‘Britons ’ + -ic .