Pushes forward (6)
I believe the answer is:
impels
'pushes forward' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for impels that I've seen before include "Drives on in simple way" , "Spurs" , "Urges or drives to do something" , "Forces, urges to action" , "Drives or forces" .)