Any disruption is negative (3)
I believe the answer is:
nay
'is negative' is the definition.
(I've seen this before)
'any disruption' is the wordplay.
'disruption' is an anagram indicator.
'any' is an anagram of 'NAY'.
(Other definitions for nay that I've seen before include "Denial" , "No - a negative vote" , "Indeed" , "In point of fact - a parliamentary vote against" , "Negative answer" .)