Resident turned Enid to Buddhism (7)
I believe the answer is:
denizen
'resident' is the definition.
(thesaurus)
'turned enid to buddhism' is the wordplay.
'turned' indicates anagramming the letters.
'to buddhism' becomes 'zen' (Zen is an example).
'enid' with letters rearranged gives 'deni'.
'deni'+'zen'='DENIZEN'
(Other definitions for denizen that I've seen before include "Resident" , "Inhabitant, occupant" , "Inhabitant (of the deep?)" , "Person in foreign country enjoying rights of natives" , "Dweller" .)