Phoney character leading enterprise in disgrace (5)
I believe the answer is:
shame
'disgrace' is the definition.
(synonyms)
'phoney character leading enterprise' is the wordplay.
'phoney' becomes 'sham' (I've seen this before).
'character leading' indicates taking the first letters.
The initial letter of 'enterprise' is 'e'.
'sham'+'e'='SHAME'
'in' acts as a link.
(Other definitions for shame that I've seen before include "Discredit - ignominy" , "Disgrace, intense regret" , "Painful emotion resulting from guilt" , "Disgrace, ignominy" , "show up" .)