Gloomy doctor has a listener (5)
I believe the answer is:
drear
'gloomy' is the definition.
(I know that gloomy can be written as drear)
'doctor has a listener' is the wordplay.
'doctor' becomes 'Dr' (abbreviation).
'has' means one lot of letters go next to another.
'a listener' becomes 'ear' (body part which hears or listens).
'dr'+'ear'='DREAR'
(Other definitions for drear that I've seen before include "Poetic dull and uninteresting" , "gloomy in poem" , "Literarily gloomy" , "Dismal (literary)" , "Depressingly dull" .)