Very melancholy at the time, giving up one's smoke (6)
I believe the answer is:
tragic
'very melancholy' is the definition.
'tragic' can be an answer for 'melancholy' (I've seen this in another clue). I'm not sure about the 'very' bit.
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for tragic that I've seen before include "Dreadful" , "Exceedingly sad" , "Calamitous, causing great sadness" , "Deeply distressing" , "Mournful" .)