Jab, nudge (4)
I believe the answer is:
prod
I believe this clue is a double definition.
'jab' is the first definition.
(synonyms)
'nudge' is the second definition.
(synonyms)
(Other definitions for prod that I've seen before include "Poke with a stick" , "Incite to action (with a stick?)" , "Poke; reminder" , "Poke, jab, nudge" , "Stimulus" .)