First, how do you pronounce it? I’ve heard
[ul]
[li]In Eggs-shell-sis[/li][li]In Eggs-sell-sis[/li][li]In Eggs-sell-shis[/li][/ul]
Second, what does it mean? It looks like Latin, maybe something along the lines of “in highest praise to God.” But I don’t speak Latin.
TIA
erm *pronounce 
In Excel cease day-oh!
It’s Latin, and means “Glory, in the highest, to God.”
You get into the question of “classic Latin” vs. “church Latin” pronunciations in the question of how to say it. The first word is “in” with the same meaning and pronunciation as English in; the last word, the dative for Deus, or God, is pronounced, in Harry Belafonte fashion, as “Day-o.” It’s the middle word that causes problems – and the Latin can be rendered two ways. It’s an ablative plural (it would be “excelse” if it were ablative singular, but like “pants” it’s a plural-only form in this usage). “Excel - sis” is a standard Englishing of the classic Latin, which actually should have a marginally longer I sound, halfway between the -ee- sound of classic Continental long I and the -ih- sound of English short I. If you say “machinations” with a hint on the unstressed I sound in the second syllable that it’s derived from “machine,” you’re close to correct. Church Latin, on the other hand, is Latin pronounced with a standard Italian (more or less Tuscan) accent, and would render this as (ex - chel - cease) with the -cel- syllable rendered as in cello. Because it is a Latin phrase in a hymn, the Church Latin is preferable but not mandatory; I’ve known a lot of Protestant renderings of the carol that use the Anglicized Classic Latin pronunciation.
In several guides to church Latin pronunciation, I have seen the recommendation that the combo xc be pronounced ksh as in bookshelf.
Thus it would be: gloria in ek-shelsis day-o
But I’ve never actually heard this pronunciation, only eks-chelsis as Polycarp indicates.
It might be worth a mention that it only makes sense as the phrase “gloria in excelsis deo” - I imagine you’re just not reading “gloria” as a foreign word, but “in excelsis deo” by itself just means “to god in the highest”, it dosen’t say what.
Gloria IN-ex-CHELL-seez DAY-oh
That’s how we always said it.
Trust me, I’ve heard pretty much every possible pronunciation. Much of the difference comes from which Latin tradition you’re dealing with.
Firstly, a small quibble: regardless of your style of Latin, “in” is pronounced “een”. Anything else is just sloppiness.
As far as “excelsis” goes, I’ve heard
egg-SHELL-cease
eggs-CHELL-cease
ek-SHELL-cease
ex-CHELL-cease
ek-SELL-cease
and
ex-KELL-cease
Personally I prefer “ek-SHELL-cease”, but as long as you’re consistent it usually doesn’t matter too much (and if you’re singing it with a group, it’s always good to all be using the same pronunciation.
[quote]
Gyrate wrote
Firstly, a small quibble: regardless of your style of Latin, “in” is pronounced “een”. Anything else is just sloppiness.*
Really? The line doesn’t conform to the pentameter or hexameter form.
I always thought the lyrics were “in aunt chelsea’s day-o.”
Can’t really help around here, as I tend to just pronounce it in Spanish (echsel-sees)…just glad for the chance to breathe after that bloody long GlooOOOooOOOooOOOoria…
I always sang this as “in ex SEL sis DAY o”.
'course, I never took Latin.
I take it Aunt Chelsea was in her youth a lady-in-waiting to Lady Mondegreen? 
I can’t agree with this. Latin had short and long versions of each vowel a, e, i, o, u: the short “i” in “incola” pronounced like the “i” in “pin”; the long “i” in “insula” pronounced like the “i” in “police”. The “i” in “in” should be a short “i” as far as I am concerned.
Me too, and I did take Latin.
Many choir directors bend the Latin a bit, for the sake of euphony (good sound.) Twenty voices singing an “x” sound in unison comes out rather harsh, so they’re coached to sing “eggshell” instead of the proper Latin.
So, forgive them, scholars. They only want to sound good.
What is called “Church Latin” pronunciation is simply modern Italian pronunciation applied to Latin. Keeping this in mind, analyzing the phonetics in the word will explain why it’s pronounced the way it is.
In Italian, the digraph sc- is pronounced “sh” when it comes before e and i. So sce is pronounced she, and sci is pronounced shi.
The letter x represents a double sound, k followed by s. So the letter combination exce- can be broken into ek- and sce-. Ek-shel-sis.
The voicing of the k sound to g, resulting in the “eggshell” pronunciation, is I think favored by choral directors to give a softer, more euphonious sound. It may be that x when intervocalic (between vowels) is voiced, to sound “gz” instead of “ks”. But I doubt that would normally apply in excelsis, since the x is followed by the unvoiced c. I guess it’s just a choral director thing.
Polycarp, now you’ve got me singing the “Banana Boat” song.
Come, Mr. tally man, tally me banana
Daylight come and me want to go home
I believe Day-oh, although it may be common among English speakers, is just wrong and the e would be pronounced short eh, deh-o. I cannot imagine the e was pronounced English fahion, because that pronounciation of e is strictly English and AFAIK the rRomans did not speak English. Only English clergy will pronounce it like that not any other country and certainly not the acient Romans.