Drive off, repulse (5)
I believe the answer is:
repel
This clue is a double definition.
'drive off' is the first definition.
(synonyms)
'repulse' is the second definition.
(I know that repulse can be written as repel)
(Other definitions for repel that I've seen before include "Be effective in controlling" , "Drive back or ward off" , "Drive back - revolt" , "Spurn" , "give you the creeps" .)