Slip quantity into vegetable and herb with duck (10)
I believe the answer is:
peccadillo
'slip' is the definition.
(I've seen this before)
'quantity into vegetable and herb with duck' is the wordplay.
I cannot quite see how this works, but
'quantity' could be 'ad' (AD is an example) and 'ad' is located in the answer.
'duck' could be 'o' (resembles zero - 'duck' in cricket) and 'o' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for peccadillo that I've seen before include "Minor transgression" , "minor faux pas" , "Minor sin or fault" , "Slip" , "A little wrong" .)