Boss dedicated to raising the stock (4)
I believe the answer is:
stud
'boss' is the definition.
(both can mean a metal decoration)
'raising the stock' is the wordplay.
'raising' becomes 'sud' (I can't explain this - if you can you should believe this answer much more).
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'stock' is an insertion indicator (stock' can mean 'fill').
'sud' placed around 't' is 'STUD'.
'dedicated to' acts as a link.
Can you help me to learn more?
(Other definitions for stud that I've seen before include "Collar button or horse farm" , "Boss; item of jewellery" , "Stallion for breeding - fastener" , "Boss; shirt fastener" , "Collar-fastener" .)