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.
('rising' can be a synonym of 'rebellion')
'coming' is the second definition.
(thesaurus)
'up' is the third definition.
('rising' can be similar in meaning to 'up')
(Other definitions for rising that I've seen before include "Ascension" , "working one's way up" , "Ascending" , "Hill" , "Upwardly mobile" .)