Corner vendor stocks sauce (5)
I believe the answer is:
nerve
'sauce' is the definition.
(I've seen this before)
'corner vendor stocks' is the wordplay.
'stocks' indicates the answer is hidden within the clue.
'NERVE' is hidden within 'corner vendor'.
(Other definitions for nerve that I've seen before include "Brass - steel" , "Sauce" , "Courage - impertinence" , "Coolness under fire" , "Fibre that carries instructions to the brain" .)