Casts off a feeling of melancholy (5)
I believe the answer is:
dumps
This clue might be a double definition.
'casts off' is the first definition.
(to cast something off is to dump or discard it)
'a feeling of melancholy' is the second definition.
'dumps' can be an answer for 'melancholy' (thesaurus). I'm unsure of the 'a feeling of' bit.
Can you help me to learn more?
(Other definitions for dumps that I've seen before include "One can be down in them" , "Ditches" , "Ends relationship" , "Rubbish tips" , "Gets rid of" .)