Damper spot had to be blasted (7)
I believe the answer is:
dashpot
'damper' is the definition.
(a dashpot dampens shock)
'spot had to be blasted' is the wordplay.
'to be blasted' indicates anagramming the letters.
'spot'+'had'='spothad'
'spothad' is an anagram of 'DASHPOT'.
(Other definitions for dashpot that I've seen before include "Damper device" , "Mechanical device" , "Device for damping vibrations" .)