Irregular cops' raid going wrong (8)
I believe the answer is:
sporadic
'irregular' is the definition.
('sporadic' can be similar in meaning to 'irregular')
'cops' raid going wrong' is the wordplay.
'going wrong' indicates an anagram.
'cops'+'raid'='copsraid'
'copsraid' is an anagram of 'SPORADIC'.
(Other definitions for sporadic that I've seen before include "Occasional - intermittent" , "Random" , "Picadors being scattered, here and there" , "Occurring irregularly" , "Occurring here and there, scattered" .)