A silly urge to quarrel (5)
I believe the answer is:
argue
'to quarrel' is the definition.
(I've seen this in another clue)
'a silly urge' is the wordplay.
'silly' indicates anagramming the letters.
'urge' is an anagram of 'rgue'.
'a'+'rgue'='ARGUE'
(Other definitions for argue that I've seen before include "Debate or disagree" , "Discuss, contend" , "Contend verbally" , "Squabble" , "Have a difference of opinion" .)