I wondered why an earlier posting by Martin Ryan had "ABCD" at the top of it, until seeing the above by Wolfgang. I'm sure that in verse two it's "Portumna" (note the "m" there). And, if "waulk'd" be the words in final verse, that only goes with "lambs"; it's similar in sense to an Irish "Wake", only of course the creatures aren't dead...

One time I heard this song, incidentally, the line given here as "rose-leaf'd May" was sung as (I'm sure) "Some people say [it's easy &c]" which is, if prosaic, at least clear in sense. I take "May" not to be the month, but an archaic word for a "Maiden"? Of course, maybe that's the lady's name...

Just shows how difficult it is to be definitive. I remember going to P K's published works for "Raglan Road", and discovering the sense/sentences were quite different from the way it seems invariably to be done.