Attack indiscriminate gunshot outside US city (9)
I believe the answer is:
onslaught
'attack' is the definition.
(an onslaught is an attack)
'indiscriminate gunshot outside us city' is the wordplay.
I cannot quite understand how this works, but
'city' could be 'la' (Los Angeles) and 'la' is present in the answer.
an anagram of 'gunshot' is 'onsught' which is located in the remaining letters.
No letters remain.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for onslaught that I've seen before include "Barrage" , "Sally" , "Violent attack" , "Vicious attack" , "Hunt goals (anag) - offensive" .)