"The Atlantic Ocean"
Translation:Y Môr Iwerydd
I believe that "Y Cefnfor Iwerydd" should be fine and is how I would say it.
It says in the notes that Môr is used in naming both seas and oceans. I suppose it's one of those instances where we expect to be able to use the literal translation, but that's not always the right way of saying it in the other language. Even if it makes sense and it'd be perfectly understood, it may not sound natural.
OK but what do we call the bit between Britain and Ireland? Dublin as an Atlantic port seems a bit odd! Cork ditto!
The sea between Britain and Ireland is the Irish Sea, and the sea between Ireland and the rest of NW Europe is the Celtic Sea, I believe.
- Môr Iwerddon - the Irish Sea
- y Môr Celtaidd - the Celtic Sea.