Promising enterprise (11)
I believe the answer is:
undertaking
This clue is a double definition.
'promising' is the first definition.
(undertaking is a kind of promising)
'enterprise' is the second definition.
(thesaurus)
(Other definitions for undertaking that I've seen before include "Formal promise; company" , "Task" , "Promise, business" , "pledge" , "Solemn business" .)