Risky commercial undertaking (7)
I believe the answer is:
venture
'risky commercial undertaking' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for venture that I've seen before include "'Nothing . . . . . . ., nothing gain'" , "Risky commercial undertaking" , "Undertaking that involves risk" , "Uncertain undertaking" , "Put at risk" .)