Discouraged man returning, having made a mistake (8)
I believe the answer is:
deterred
'discouraged' is the definition.
('deter' can be a synonym of 'discourage')
'man returning having made a mistake' is the wordplay.
'man' becomes 'ted' (Ted is a man's name).
'returning' is a reversal indicator.
'having' is a charade indicator (letters next to each other).
'made a mistake' becomes 'erred' ('err' can be a synonym of 'make a mistake').
'ted' reversed gives 'det'.
'det'+'erred'='DETERRED'
(Other definitions for deterred that I've seen before include "Prevented or discouraged from doing something" , "Checked" , "given caution" , "Discourage (someone from doing something)" , "Discouraged, put off" .)