Lyrics:

Watermark (With Translation)
Cursum Perficio

Cursum perficio. I am making an end to my course.
Verbum sapienti: A word to the wise:
quo plus habent, the more [people] have
eo plus cupiunt. the more they want.
Post nubila, Phoebus After the clouds, Phoebus (1)
Iternum Over and over again (2)


Phoebus was one of the names for the Sun god,
which may be more famous as Apollo (Greek).
It is notable that the Sun is a male.
The word 'iternum' does not exist;
it could either be a misspelling for 'eternum' (eternal),
which is unlikely since it is very rare that an adjective
be used as an adverb, or for 'iterum' (again and again)
which is in fact an adverb and makes a little more sense (!!).
The meaning of 'cursum perficio' is actually best explained
by the footnote to the lyrics:
Enya was inspired by these words she saw on Marylin Monroe's
last house, where they were taken to mean 'my journey ends here'.
It is a rather 'free' translation, but it's probably a very good
way to convey the meaning of Latin, which has a way of saying
things that is very distant from modern-day English.
The fact that those words turned out to be prophetical only
adds to the power of the song