Hit hard, run a mile (3)
I believe the answer is:
ram
'hit hard' is the definition.
(I've seen this in another clue)
'run a mile' is the wordplay.
'run' becomes 'r' (cricket abbreviation).
'mile' becomes 'm' (common abbreviation).
'r'+'a'+'m'='RAM'
(Other definitions for ram that I've seen before include "Tamp" , "Pound" , "Male sheep - bash into it" , "Drive hard" , "Deliberately collide with" .)