Rejected as unfashionable by an exclusive social class say (7)
I believe the answer is:
outcast
'rejected' is the definition.
(thesaurus)
'unfashionable by an exclusive social class say' is the wordplay.
'unfashionable' becomes 'out' ('out' can be a synonym of 'unfashionable').
'by' is a charade indicator (letters next to each other).
'an exclusive social class' becomes 'caste' (I've seen this before).
'say' indicates a 'sounds like' (homophone) clue.
'caste' is a homophone of 'cast'.
'out'+'cast'='OUTCAST'
'as' is the link.
(Other definitions for outcast that I've seen before include "Exile" , "He has been evicted from society" , "One is excluded from society" , "Rejected individual" , "One has been rejected by friends or society" .)