Say nothing revolutionary, or just a little bit (5)
I believe the answer is:
shred
'a little bit' is the definition.
(both can mean a small amount)
'say nothing revolutionary' is the wordplay.
'say nothing' becomes 'sh' ('sh' is said to tell someone to say nothing).
'revolutionary' becomes 'red' (informal term for communist).
'sh'+'red'='SHRED'
'or just' is the link.
(Other definitions for shred that I've seen before include "Strip of material; a very small amount" , "Tear into tiny pieces" , "Tear into scraps" , "Cut up; a small amount" , "Rip up" .)