Being lumbered with melancholy (4)
I believe the answer is:
glum
'melancholy' is the definition.
(I've seen this in another clue)
'being lumbered with' is the wordplay.
'with' indicates a hidden word.
'GLUM' can be found hidden inside 'being lumbered'.
(Other definitions for glum that I've seen before include "Forlorn" , "Moody and depressed" , "Down at the mouth, gloomy" , "Down in the mouth, depressed" , "Melancholy" .)