Company's vegetable product (3)
I believe the answer is:
cos
'company's vegetable' is the definition.
'cos' can be an answer for 'vegetable' (cos is a kind of vegetable). I'm not certain of the 'company's' bit.
'product' is the wordplay.
I cannot quite see how this works, but
'product' could be 'os' (OS is an example) and 'os' is present in the answer.
A single letter 'c' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for cos that I've seen before include "Islanders here" , "Chief of Staff" , "A long-leaved lettuce" , "something of a salad" , "naturally having longer leaves than most" .)