That of the cat that ate the duck? (4)
I believe the answer is:
coat
'that of' is the definition.
I can't judge whether this defines the answer.
'cat that ate the duck?' is the wordplay.
'that ate' indicates putting letters inside.
'the duck?' becomes 'o' (resembles zero - 'duck' in cricket).
'cat' placed around 'o' is 'COAT'.
'the' is the link.
Can you help me to learn more?
(Other definitions for coat that I've seen before include "Warm outerwear" , "Fleece" , "Outer garment" , "Apply layer" , "blanket" .)