A few indological inquiries

[Gerard Huet]

Greetings to distinguished indology scholars.
I have a few questions pertaining to indian architecture and iconography.

The first set of questions concerns Orissan architecture.

1. In Orissa, the main structure of a temple, as well as its inner
sanctuary, is usually called "deul". This does not appear to be a sanskrit
word, although it could plausibly be derived from the root dIv/dev.
What is the accepted etymology of this term?

2. The room next to the deul is called "jaganmohana", which is sanskrit
for "Illusion of the World" or "World Illusion" if I am not mistaken, although
this word does not appear in Monet-Williams. What is the standard explanation
for this terminology?

Next I have a few questions about religious iconography.

1. The halo of flames that sometimes frames idols such as Na.tarAja is
usually called "prabhAma.n.dala" which means "Circle of Light". This
etimology is pretty clear, although it is not clear to me whether the
substantive prabhA comes form the verb pra-bhA or from pra-bhAs, since
the roots bhA and bhAs have very close meanings.
Sometimes this halo is referred to as "prabhAvali" where "vali", which
usually means wrinkle in sanskrit, is sometimes spelled "valI" or even
"vallI". Which is the correct spelling, and is the proper translation
"festooned with light"?
Furthermore, what is the precise symbolism of this ornament? The word
"prabhA" (light) seems to be preferred to "agni" (fire), which would seem
more appropriate if one wanted to evoque the destruction of the world
or some other fiery attribute.
I have also encountered the terminology "tiruvAci" or "tiruvAsi", which is
definitely not indo-european. Could some tamil or other language specialist 
explain this terminology?

2. 'Siva Na.tarAja is represented dancing its cosmic dance. Should this
posture be referred to as "nadAnta" or as "tA.ndava", or even as
"Ananda-tA.ndava"?

3. 'Siva Na.tarAja is stepping on a dwarf figure called "apasmAra puru.sa"
which means "epileptic person". I have also seen references to
the rAk.sasa Muyalaka, or MulayakaN or Musalagan. Could some scholar
explain to me the proper spelling, etymology, and symbolism of this figure?
More generally, what is the treatise which discusses such matters with
authority?

Thank you very much for your help. I suggest that you answer by email,
and I shall summarize the opinions to this list.

Gerard.Huet at inria.fr