Overblown publicity (4)
I believe the answer is:
hype
'overblown publicity' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for hype that I've seen before include "Excessive publicity" , "Extravagant publicity or promotion" , "Extravagant promotion of a person or product" , "Excess publicity" , "racket" .)