A party radical is revered (6)
I believe the answer is:
adored
'is revered' is the definition.
(synonyms)
'a party radical' is the wordplay.
'party' becomes 'do' (do can informally mean a party).
'radical' becomes 'red' (red can mean a communist).
'a'+'do'+'red'='ADORED'
(Other definitions for adored that I've seen before include "Worshipped and venerated" , "Loved dearly" , "hugely popular" , "Deeply respected" , "enjoyed very much" .)