The
Brittonic,
Brythonic or
British Celtic languages (, , ) form one of the two branches of the
Insular Celtic language family; the other is
Goidelic. The name
Brythonic was derived by
Welsh Celticist John Rhys from the
Welsh word
Brython, meaning an indigenous
Briton as opposed to an
Anglo-Saxon or
Gael. The name
Brittonic derives ultimately from the name
Prettanike, recorded by Greek authors for the
British Isles. Some authors reserve the term
Brittonic for the modified later Brittonic languages after about AD 600.