Bolt from the blue? (9)
I believe the answer is:
lightning
'bolt from the blue?' is the definition.
(the blue can mean the sky)
'bolt from' is the wordplay.
I cannot quite understand how this works, but
'from' could be 'in' (I've seen this in other clues) and 'in' is present in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for lightning that I've seen before include "Natural electrical discharge" , "Discharge of electricity in the atmosphere" , "Precaution against electrical storms" , "Atmospheric discharge" , "Weather featuring with 9" .)