Exploits us two ways (4)
I believe the answer is:
uses
'exploits' is the definition.
(use is a kind of exploit)
'us two ways' is the wordplay.
'two ways' means two replacements for 'way'.
'way' becomes 'e' (Compass direction - East).
'way' becomes 's' (Compass direction - South).
'us'+'e'+'s'='USES'
(Other definitions for uses that I've seen before include "deployments" , "Exercises" , "Puts into service" , "Operates" , "Employs" .)