Unusual using Egyptian god with religious teaching (4)
I believe the answer is:
rare
'unusual' is the definition.
(thesaurus)
'egyptian god with religious teaching' is the wordplay.
'egyptian god' becomes 'ra' (Ra is an example).
'with' is a charade indicator (letters next to each other).
'religious teaching' becomes 're' (religious education).
'ra'+'re'='RARE'
'using' acts as a link.
(Other definitions for rare that I've seen before include "Ben Jonson was considered so" , "Rear up, being scarce" , "Scarce as hen's teeth!" , "may be bloody" , "having few matches?" .)