Leave, having left honour in despondency (5)
I believe the answer is:
gloom
'despondency' is the definition.
(I've seen this in another clue)
'leave having left honour' is the wordplay.
'leave' becomes 'go' (to go is to depart or leave).
'having' is an insertion indicator.
'left' becomes 'l' (common abbreviation).
'honour' becomes 'om'.
'go' placed around 'l' is 'glo'.
'glo'+'om'='GLOOM'
'in' acts as a link.
(Other definitions for gloom that I've seen before include "Near-darkness - misery" , "Partial darkness" , "Darkness; depression" , "Murk" , "Betting figures" .)