There's a rebellion coming up (6)
I believe the answer is:
rising
I believe this is a triple definition!
'there's a rebellion' is the first definition.
(synonyms)
'coming' is the second definition.
(thesaurus)
'up' is the third definition.
(similar in meaning)
(Other definitions for rising that I've seen before include "Ascension" , "working one's way up" , "Ascending" , "Hill" , "Upwardly mobile" .)