Spur, incite (4)
I believe the answer is:
goad
This clue is a double definition.
'spur' is the first definition.
(I know that spur is a kind of goad)
'incite' is the second definition.
(I know that goad is a kind of incite)
(Other definitions for goad that I've seen before include "'Prod, urge (4)'" , "Spur, prod" , "Incite to action" , "Cattle prod" , "Cattle-driving spike" .)