Minor setback (6)
I believe the answer is:
hiccup
'minor setback' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for hiccup that I've seen before include "Snag" , "Reflex spasm of the diaphragm" , "Sudden throat sound or minor mishap" , "Involuntary glottal closure" , "Glitch" .)