Converted idolater's adapted (8)
I believe the answer is:
tailored
'adapted' is the definition.
(I've seen this before)
'converted idolater's' is the wordplay.
'converted' indicates an anagram.
'idolater' anagrammed gives 'TAILORED'.
(Other definitions for tailored that I've seen before include "cut to size" , "Made garments, suits perhaps" , "Cut to fit" , "Fitted to requirements" , "Made to measure for idolater" .)