Revolutionary crowd, one interrupting a race, creating outrage (11)
I believe the answer is:
abomination
'outrage' is the definition.
(thesaurus)
'revolutionary crowd one interrupting a race' is the wordplay.
'revolutionary crowd' becomes 'bomi' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'one interrupting' is an insertion indicator.
'race' becomes 'nation' (both can mean a national or ethnic group).
'a'+'nation'='anation'
'bomi' going within 'anation' is 'ABOMINATION'.
'creating' is the link.
(Other definitions for abomination that I've seen before include "Feeling of hatred or disgust" , "Cause of hatred or disgust" , "Action that is vile" .)