Sensible to take tablet for discharge (8)
I believe the answer is:
spillage
'for discharge' is the definition.
(I've seen this before)
'sensible to take tablet' is the wordplay.
'sensible' becomes 'sage' (I can't explain this - if you can you should give a lot more credence to this answer).
'to take' indicates putting letters inside (inserted letters are taken in).
'tablet' becomes 'pill' (synonyms).
'sage' enclosing 'pill' is 'SPILLAGE'.
Can you help me to learn more?
(Other definitions for spillage that I've seen before include "Liquor lost" , "result of accident" , "waste material" , "upset" , "Something accidentally lost" .)