An ultra revolutionary is unaffected (7)
I believe the answer is:
natural
'unaffected' is the definition.
(synonyms)
'an ultra revolutionary' is the wordplay.
'revolutionary' is an anagram indicator.
'an'+'ultra'='anultra'
'anultra' is an anagram of 'NATURAL'.
'is' acts as a link.
(Other definitions for natural that I've seen before include "person regarded as certain to qualify" , "character on the staff" , "Not artificial or affected" , "(In music) neither sharp nor flat" , "Sign on staff" .)