Duck from down under about to be introduced to west (4)
I believe the answer is:
zero
'duck' is the definition.
(thesaurus)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for zero that I've seen before include "Nada" , "You'll find nothing" , "Loser" , "The hour to leave" , "has no effect, in addition" .)