Wilt when doctor gets nothing to work (5)
I believe the answer is:
droop
'wilt' is the definition.
(I know that wilt can be written as droop)
'doctor gets nothing to work' is the wordplay.
'doctor' becomes 'Dr' (abbreviation).
'gets' means one lot of letters go next to another.
'nothing' becomes 'o' (looks like zero - 0).
'to work' becomes 'op' (abbreviation for opus).
'dr'+'o'+'op'='DROOP'
'when' is the link.
(Other definitions for droop that I've seen before include "Sag, hang down" , "Hang downwards, lose strength or spirit" , "male problem?" , "Sag, wilt" , "lose heart" .)