Courage of a he-man (5)
I believe the answer is:
heart
'courage' is the definition.
(heart is a kind of courage)
'a he-man' is the wordplay.
'man' becomes 'art' ().
'he'+'art'='HEART'
'of' acts as a link.
(Other definitions for heart that I've seen before include "Playing card - pity" , "bottle" , "Core - card" , "one in suit" , "Muscular organ - compassion" .)