Repudiate Pluto, now reviewed (6)
I believe the answer is:
disown
'repudiate' is the definition.
(I know that repudiate can be written as disown)
'pluto now reviewed' is the wordplay.
'pluto' becomes 'dis' (another name for the mythical god).
'reviewed' is an anagram indicator (letters reviewed or revised).
'now' anagrammed gives 'own'.
'dis'+'own'='DISOWN'
(Other definitions for disown that I've seen before include "Repudiate - disinherit" , "Repudiate, disclaim" , "Reject all connection or relationship with" , "Reject all connection with, refuse to acknowledge" , "Abnegate" .)