Drive or urge forward (5)
I believe the answer is:
impel
I believe this is a double definition.
'drive' is the first definition.
(I know that drive is a kind of impel)
'urge forward' is the second definition.
(I've seen this before)
(Other definitions for impel that I've seen before include "Urge or propel" , "Force forwards" , "Hold together" , "Oblige" , "Press on - drive forward" .)