Petty fight (4)
I believe the answer is:
spat
'petty fight' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for spat that I've seen before include "Expectorated in slight quarrel" , "Made gesture of contempt" , "Disagreement" , "Little quarrel - leg wear" , "Legging covering instep and ankles" .)