Sad, glum (4)
I believe this is a double definition.
'sad' is the first definition.
(I know that sad can be written as blue)
'glum' is the second definition.
(I've seen this before)
(Other definitions for blue that I've seen before include "Dirty" , "Such humour < makes conservative" , "University sportsman - a shade - depressed" , "Dispirited in cerulean way" , "See 7 Across" .)
This clue is a double definition.
'sad' is the first definition.
(I've seen this before)
'glum' is the second definition.
(thesaurus)
(Other definitions for doleful that I've seen before include "Dismal" , "Dreary" , "Showing great melancholy" , "Miserable" , "Causing grief; sorrowful" .)