Slip into supermarket for reduction: avoid one with bill (6,4)
I believe the answer is:
donald duck
'one with bill' is the definition.
(ducks have bills)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for donald duck that I've seen before include "Disney cartoon character" , "Walt Disney character" , "Bradman getting no runs" , "would be a figure of fun" , "Screen favourite" .)