Disciple repentant finally, embraced by Lord (5)
I believe the answer is:
peter
'disciple' is the definition.
(thesaurus)
'repentant finally embraced by lord' is the wordplay.
'finally' says to take the final letters.
'embraced by' means one lot of letters goes inside another.
'lord' becomes 'peer' (peer is a kind of lord).
The last letter of 'repentant' is 't'.
't' going inside 'peer' is 'PETER'.
(Other definitions for peter that I've seen before include "- Pan, eternal youth" , "Fellow < safe" , "Boy's name - safe" , "Saint's name" , "emperor" .)