Capone, say, providing weapons is scary! (8)
I believe the answer is:
alarming
'is scary' is the definition.
(similar in meaning)
'capone say providing' is the wordplay.
'capone say' becomes 'Al' (gangster Al Capone).
'providing' becomes 'arming' (arming is a kind of providing).
'al'+'arming'='ALARMING'
'weapons' is the link.
This may not be correct. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for alarming that I've seen before include "Fearsome" , "Dangerous" , "Striking with fear" , "causing fright" , "Worrying or disturbing" .)