Notice about public relations fling (5)
I believe the answer is:
spree
'fling' is the definition.
('spree' can be a synonym of 'fling')
'notice about public relations' is the wordplay.
'notice' becomes 'see' (I've seen this before).
'about' indicates putting letters inside.
'public relations' becomes 'pr'.
'see' going around 'pr' is 'SPREE'.
(Other definitions for spree that I've seen before include "Binge" , "Revel" , "Splurge" , "Spell of wild activity" , "Session of over-indulgence" .)