A risky venture? Help! (4)
I believe the answer is:
abet
'help' is the definition.
(I've seen this before)
'a risky venture?' is the wordplay.
'risky venture?' becomes 'bet' ().
'a'+'bet'='ABET'
(Other definitions for abet that I've seen before include "Assist illegally" , "Incite, help" , "Help to do something wrong" , "Aid in offence" , "Make good" .)