Nonsense written about one uprising (4)
I believe the answer is:
riot
'uprising' is the definition.
(I've seen this before)
'nonsense written about one' is the wordplay.
'nonsense' becomes 'rot' (I've seen this before).
'written about' is an insertion indicator.
'one' becomes 'i' (Roman numeral).
'rot' enclosing 'i' is 'RIOT'.
(Other definitions for riot that I've seen before include "Civil disorder" , "unrestrained revelry" , "Disturbance by unruly mob" , "Run amok" , "Rowdy behaviour" .)