Flat deposit previously held in stock (6)
I believe the answer is:
cowpat
'flat' is the definition.
Both the definition and answer are singular nouns.
Maybe there's a link between them I don't understand?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for cowpat that I've seen before include "You don't want to put your foot in it" , "Piece of cattle dung" , "Bovine dung" , "'In a field, one might step in one (6)'" , "Brown deposit in a field?" .)