Contrive dull, occasionally somewhat revolutionary plot (7)
I believe the answer is:
collude
'plot' is the definition.
(I've seen this before)
'contrive dull occasionally somewhat revolutionary' is the wordplay.
'somewhat' indicates a hidden word.
'revolutionary' is a reversal indicator (letters revolve around).
'edulloc' can be found hidden inside 'contrive dull occasionally'.
'edulloc' backwards is 'COLLUDE'.
(Other definitions for collude that I've seen before include "Conspire fraudulently" , "Conspire together" , "Conspire to defraud" , "Come to a secret and devious understanding" , "Be in cahoots" .)