Man's crisis: awful vanity (10)
I believe the answer is:
narcissism
'vanity' is the definition.
(I know that narcissism is a type of vanity)
'man's crisis awful' is the wordplay.
'awful' indicates anagramming the letters.
'mans'+'crisis'='manscrisis'
'manscrisis' with letters rearranged gives 'NARCISSISM'.
(Other definitions for narcissism that I've seen before include "Self-obsession" , "show great self-interest?" , "Self-love" , "Vanity" , "Admiration for oneself" .)