Risk onset of hail disrupting outing, perhaps (6)
I believe the answer is:
threat
'risk' is the definition.
(I've seen this before)
'onset of hail disrupting outing perhaps' is the wordplay.
'onset of' suggests taking the first letters.
'disrupting' is an insertion indicator (inside letters 'disrupt' the flow of outside one).
'outing perhaps' becomes 'treat' (I am not sure about the 'perhaps' bit.).
The initial letter of 'hail' is 'h'.
'h' put into 'treat' is 'THREAT'.
Can you help me to learn more?
(Other definitions for threat that I've seen before include "Endangerment" , "An intimidating warning" , "Warning of intent to harm" , "Menace of impending evil" , "A warning of harm to come" .)