Look sad, like a doctor getting nothing for an operation (5)
I believe the answer is:
droop
'look sad' is the definition.
I can't judge whether this definition defines the answer.
'doctor getting nothing for an operation' is the wordplay.
'doctor' becomes 'dr' (abbreviation).
'getting' means one lot of letters go next to another.
'nothing' becomes 'O' (looks like zero - 0).
'for' is a charade indicator (letters next to each other).
'an operation' becomes 'op'.
'dr'+'o'+'op'='DROOP'
'like a' acts as a link.
Can you help me to learn more?
(Other definitions for droop that I've seen before include "Dangle" , "Hang limply" , "sink" , "Sag, wilt" , "Hang downwards, lose strength or spirit" .)