Rum agent stupidly causing row (8)
I believe the answer is:
argument
'row' is the definition.
(I've seen this before)
'rum agent stupidly' is the wordplay.
'stupidly' is an anagram indicator (a stupid ordering of the letters).
'rum'+'agent'='rumagent'
'rumagent' is an anagram of 'ARGUMENT'.
'causing' is the link.
(Other definitions for argument that I've seen before include "Contentious debate" , "Debate - disagreement" , "Line of reasoning" , "Tiff" , "Discussion - line of proof" .)