Meat jelly with a reduced flavour (5)
I believe the answer is:
aspic
'meat jelly' is the definition.
(I've seen this before)
'a reduced flavour' is the wordplay.
'reduced' means to remove the last letter.
'flavour' becomes 'spice' (spicing is a kind of flavouring).
'spice' with its last letter removed is 'spic'.
'a'+'spic'='ASPIC'
'with' acts as a link.
(Other definitions for aspic that I've seen before include "that's clear?" , "Preservative jelly" , "Setter" , "Jelly based on fish or meat stock" , "Savoury jelly for coating meats and eggs" .)