Prevent them from getting involved in dumb ruckus over there (4)
I believe the answer is:
curb
'prevent' is the definition.
(thesaurus)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for curb that I've seen before include "Restrain, inhibit" , "[LIMITATION]" , "Rein in" , "Bit - restraint" , "Restrain, perhaps your enthusiasm" .)