'Aggivessana'

Dear Jim et al,

Christine was asking in one of her posts what 'Aggivessana' meant, I
think it is used in several places to address the Nigghantha people,
and I know that 'aggi' means fire, while 'vessana' has something to do
with dwelling, doesn't it (just guessing here)?  Would this mean that
they were fire worshippers too?  Or just that they are warm, living
people?

Thanks in advance,

Amara