> What do the modern terms "Prydain" and "prydeinig" mean, exactly? > Are they simply equivalent to 'Britain' and 'British' (i.e. loosely > used for UK)? And what is the Welsh for 'Great Britain' (UK minus > Northern Ireland)? > > You are correct in your assumption that Prydain = Britain, and Prydeinig = British. I would normally use Prydain Fawr to mean Great Britain, but in the context of Wales, Scotland, England, and Northern Ireland. N.I. is inclusive, as far as I know, but The Republic is not. It's Great Britain and The Republic of Ireland. What do other people think? Rob Griffiths