Set off strikes with uncertainty (4)
I believe the answer is:
risk
'uncertainty' is the definition.
(thesaurus)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for risk that I've seen before include "Assessment of potential dangers -- any silk saris (anag)" , "Danger or hazard" , "Element of uncertainty" , "Expose to danger" , "Jeopardy" .)