Minor squabble (5)
'minor squabble' 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 "Small quarrel between Pats" , "Expelled" , "Trivial quarrel" , "Pat's involved in petty quarrel" , "Slight quarrel - ejected saliva" .)
(Other definitions for setto that I've seen before include "Start" , "argument" , "battle" , "Fight" .)