Doctor and son left nothing for carrier of disease (8)
I believe the answer is:
mosquito
'carrier of disease' is the definition.
(I've seen this before)
'doctor and son left nothing' is the wordplay.
'doctor' becomes 'mo' (medical officer).
'and' is a charade indicator (letters next to each other).
'son left' becomes 'squit' (I can't explain this - if you can you should believe this answer much more).
'nothing' becomes 'o' (looks like zero - 0).
'mo'+'squit'+'o'='MOSQUITO'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for mosquito that I've seen before include "Malaria-transmitting fly" , "Biting bug" , "Malaria carrier" , "Insect - WWII fighter-bomber" , "Insect, the female of which sucks blood" .)