Hear about a user involved in the Exchequer (8)
I believe the answer is:
treasury
'exchequer' is the definition.
('treasury' can be a synonym of 'exchequer')
'hear about a user involved' is the wordplay.
'hear' becomes 'try' ('try' can be a synonym of 'hear'**).
'about' indicates an anagram.
'involved' means one lot of letters goes inside another.
'a'+'user'='auser'
'auser' anagrammed gives 'easur'.
'try' placed around 'easur' is 'TREASURY'.
'in the' acts as a link.
(Other definitions for treasury that I've seen before include "Government department in charge of finances" , "Government finance department" , "Repository of government funds" , "Government financial department" , "Exchequer - store for valuables" .)