Revulsion from inside somewhat reduced (6)
I believe the answer is:
hatred
'revulsion' is the definition.
(thesaurus)
'from inside somewhat reduced' is the wordplay.
'from' indicates the answer is hidden within the clue.
'HATRED' is hidden within 'inside somewhat reduced'.
(Other definitions for hatred that I've seen before include "Great dislike" , "Antipathy" , "Animus" , "Intense dislike" , "Dearth (anag)" .)