On this topic, I just today spent an hour or two (maybe more) researching the origins of the name Magus - that sort of etymology is actually quite interesting to me, actually. Anyway, I noticed on the Chrono Shock forums that one of the theories put forward was that it was a Chaldean name, and thus would originally be pronounced as the plural is, with a j (ie. Mah-jus.) However, from what I have found (and I have attempted to vary my sources beyond the wiki-pedia sites, as the reliability of those is questionable), that is not the case. Most of this is known, I just figured I would reiterate more conclusively.
Firstly, proving my suspicions correct, the name is not Chaldean. The Chaldeans were a group living around the area of Ur (if anyone knows were this is, that is; it is in mid-Iraq nowadays, some ways south of Baghdad.) The term 'Magi', however, has something of a different origin. It comes to us directly from Latin, wherein the word Magus is used to denote a wise man or even sorcerer. In this context, the true pronounciation is Mah-gus. I would also wager, with reliable surity, that Magi would then in Latin be Mahg-ee, even as angelus is ahn-gel-uhs, with a harsh g. However, in Ecclesiastical, that is, Church Latin, the pronounciation of this g becomes a j, thus yielding our modern 'ain-jel'. A similar thing, I believe, occured to Magi, and it became 'Mah-jai'. I am not certain why Magus did not suffer the same fate, yet it appears to remain in common speech similar to the old Latin, save for the a, which is now an 'ay', rather than a short 'ah'.
Now let us take another step backward.
Just like the example of 'angel', magus comes from the Greek/Hellenic vocabulary (where angel is aggelos, the gg being pronounced ng.) Magus here is written as Magos, with the o being pronounced as the u in but - there are different versions, however, depending on the part of speech it is, such as Magous, and Magou, but they are mostly incidental. Of interest, however, is that Magos is not directly a word for sorcerer or magic. Tekhnay, or skill, is the more indigenous word. Magos does, however, figure into at least one other word meaning magician, and that is Magikos.
Anyway, here things become a little shaky.
Magos is not a native Hellenic word. It is rather Persian. Now, the confusion between Persian and Chaldean is understandable, as the Chaldeans lived in an area that was at a time occupied by the Medo Persian Empire. But natively, the Persians live south west of the area, and are about as far east a people as one can get without being on the doorstep of India. Now, the Persians and Medes came to power in succession to the Neo Babylonians, in the mid 500s BC. The historian Herodotus (the first historian, actually) speaks of a certain Median tribe or caste (here seems to be a hazy area for me, as different sources speak of it differently), a member of whom he termed a Magos (or, in English, Magian.) This word, according to one site (and a wiki-pedia one, so I approach it with caution) comes from Magupati, a Persian word, and certain roots denoting strength. One says that magus actually, in origin, means 'mighty one'. Also said is:
The Persian word is a u-stem adjective from an Indo-Iranian root *magh "powerful, rich" also continued in Sanskrit magha "gift, wealth", magha-vant "generous" (a name of Indra). And, far, far more reliable than these wiki sites, the Oxford Dictionary speaks of it as coming from magu-s, which I take to mean that the s is an addition to a root-word. By this, I think that the original Persian pronounciation did indeed use the harsher g sound rather than the j.
But whatever it may mean, they came to be known as priests and astrologers, hence the Hellenes usage of it to denote magicans, whence the Latins and later we inherit it. And it can then be, with near final conclusivity, that the proper, if not common, pronounciation of Magus is Mah-gus.
Oh, and as for the sources I used in coming to this conclusion...
The pronounciation of Greek/Hellenic and Latin I knew so did not look up, but the history of the word I did not, and looked at several places, the chief of these being:
(A fully reliable site, as it is the online version of a respected Greek Lexicon.):
http://www.perseus.tufts.edu/cgi-bin/ptext?layout.reflang=greek;layout.refembed=2;layout.refwordcount=1;layout.reflookup=%2Ama%2Fgou;doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3D%2364449(A wiki-based site):
http://www.nationmaster.com/encyclopedia/List-of-English-words-of-Persian-origin(and wikipedia itself):
http://en.wikipedia.org/wiki/MagiSo you may look for yourself. None of these things are exceptionally hard to find, save maybe for the Lexicon site (that is not one of those commonly known ones, though it is one of my favourite sites on the internet.)
