Shocks draining energy from certain forces (9)
I believe the answer is:
surprises
'shocks draining' is the definition.
'surprises' can be an answer for 'shocks' (I've seen this before). I'm unsure of the 'draining' bit.
'energy from certain forces' is the wordplay.
'energy' becomes 'e' (physics symbol as in E=mcr).
'from' is a deletion indicator.
'certain' becomes 'sure' (synonyms).
'forces' becomes 'prises' (I can't explain this - if you can you should give a lot more credence to this answer).
'sure' with 'e' taken away is 'sur'.
'sur'+'prises'='SURPRISES'
Can you help me to learn more?
(Other definitions for surprises that I've seen before include "Shocks" , "Sudden, unexpected events" , "Astonishes" , "unexpected things of life" , "bowls over" .)