Mush mixed into treatment for sore throat that keeps you quiet (4,5)
I believe the answer is:
hush money
'sore throat that keeps you quiet' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'mush mixed into treatment' is the wordplay.
'mixed' indicates anagramming the letters.
'into' means one lot of letters goes inside another.
'treatment' becomes 'honey' (I can't justify this - if you can you should believe this answer much more).
'mush' with letters rearranged gives 'ushm'.
'ushm' inserted inside 'honey' is 'HUSH MONEY'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for hush money that I've seen before include "sweetener" , "Payment to keep another silent" , "Price of silence" , "Payment to ensure silence" .)