Duckbill (8)
I believe the answer is:
platypus
'duckbill' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for platypus that I've seen before include "Primitive mammal, duck-billed" , "Australian mammal with large bill and webbed feet" , "Australian resident" , "Exotic animal" , "Australian mammal with duckbill" .)