Little old star, no posh god (6)
I believe the answer is:
osiris
'posh god' is the definition.
'osiris' can be an answer for 'god' (Egyptian god). I am not certain of the 'posh' bit.
'little old star no' is the wordplay.
'little' indicates taking the first letters.
'star no' becomes 'siris' (I can't justify this - if you can you should give a lot more credence to this answer).
The first letter of 'old' is 'o'.
'o'+'siris'='OSIRIS'
(Other definitions for osiris that I've seen before include "Egyptian deity" , "one held to be divine" , "one Egyptians worshipped" , "Egyptian god of the underworld" , "once highly esteemed by Egyptians" .)