Hard fall may reveal this moral (9)
I believe the answer is:
hailstorm
'hard fall' is the definition.
'hailstorm' can be an answer for 'fall' (I have seen 'Fall of ice ' mean 'hailstorm' so perhaps 'fall' could also mean 'hailstorm'). I'm unsure of the 'hard' bit.
'reveal this moral' is the wordplay.
'reveal' indicates an anagram.
'this'+'moral'='thismoral'
'thismoral' anagrammed gives 'HAILSTORM'.
'may' acts as a link.
Can you help me to learn more?
(Other definitions for hailstorm that I've seen before include "rough weather" , "when Sky drops The Stones?" , "Violent shower" , "Cold shower" , "Frozen rain squall" .)