Short road to defeat (4)
I believe the answer is:
rout
'defeat' is the definition.
(rout is a kind of defeat)
'short road' is the wordplay.
'short' means to remove the last letter.
'road' becomes 'route' ('route' can be a synonym of 'road').
'route' with its last letter removed is 'ROUT'.
'to' acts as a link.
(Other definitions for rout that I've seen before include "Headlong flight" , "Put to flight in disarray" , "Inflict heavy defeat on" , "Put to flight on tour" , "Defeat utterly" .)