Okay, going along with the Hijack here, but only because I had to learn latin at school, so for once I may officialy uphold my "Dr. Wisebottom" title.

"pie" is the Vocative (addressing case) form of "pius", which as mode has already correctly diagnosed to live on, disguised with an extra "o" in your "pious".
Same goes for "domine", where "dominus" obviously translates to "lord".
They're addressing a "pious lord", who is further described by "Jesu" (Vocative form of "Jesus", that is).
"dona" is imperative of "donare", of which you still find leftovers in "donate", thus translating to "give".
"eis" is a bit trickier, since pronouns in latin are a bit special. It's dative of "is,ea,id", the "pointing pronoun". -- "to them".
"requiem" -- you probably guessed it. Accusative of "requies" (remains in "quiet") -- "rest."
Sorry Ripsaw, but that myth is BUSTED.

Latin-geek out.