Disease claiming a flipping unpleasant pleasure-seeker
I believe the answer is:
gadabout
'pleasure-seeker' is the definition.
(I've seen this before)
'disease claiming a flipping unpleasant' is the wordplay.
'disease' becomes 'gout' (gout is a kind of disease**).
'claiming' is an insertion indicator.
'flipping' says the letters should be written backwards.
'unpleasant' becomes 'bad'.
'bad' in reverse letter order is 'dab'.
'a'+'dab'='adab'
'gout' placed around 'adab' is 'GADABOUT'.
(Other definitions for gadabout that I've seen before include "Pleasure-seeker" , "restless sort" , "Person who goes around aimlessly" , "Vagrant" , "restless type" .)