Kent town fed up, we hear, producing old-fashioned advertising (8,5)
I believe the answer is:
sandwich board
'old-fashioned advertising' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'kent town fed up we hear' is the wordplay.
'kent town' becomes 'sandwich' (I can't justify this - if you can you should give a lot more credence to this answer).
'fed up' becomes 'bored' (I've seen this before).
'we hear' indicates a 'sounds like' (homophone) clue.
'bored' sounds like 'board'.
'sandwich'+'board'='SANDWICH BOARD'
'producing' acts as a link.
Can you help me to learn more?
(Other definitions for sandwich board that I've seen before include "Ad-carrier strapped on" , "something used for advertising" , "Portable advertising placard" , "Moving advertisement" , "Advertisement carried up and down the street" .)