New Pope is to converse (8)
I believe the answer is:
opposite
'converse' is the definition.
(I've seen this before)
'new pope is to' is the wordplay.
'new' indicates an anagram.
'pope'+'is'+'to'='popeisto'
'popeisto' is an anagram of 'OPPOSITE'.
(Other definitions for opposite that I've seen before include "Directly facing each other" , "Reverse or antithesis" , "Contrary, antipode" , "Converse" , "Corresponding" .)