Aristocracy is offensive (4)
I believe the answer is:
rank
I believe this is a double definition.
'aristocracy' is the first definition.
(thesaurus)
'offensive' is the second definition.
('rank' can be similar in meaning to 'offensive')
'is' acts as a link.
(Other definitions for rank that I've seen before include "Fetid" , "High social standing" , "Line of people" , "stink in > class" , "Social class" .)