Push gently (4)
'push gently' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for nudge that I've seen before include "A gentle reminder?" , "Push with the elbow" , "Gentle encouragement" , "Jogger" , "Give a reminder" .)
(Other definitions for coax that I've seen before include "Attempt to manipulate" , "Flatter" , "Carefully manipulate" , "Wheedle, cajole" , "lead not to get wires crossed?" .)