Exploit tramps regularly (3)
I believe the answer is:
tap
'exploit' is the definition.
(to tap is to exploit or make use of something)
'tramps regularly' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
The alternating letters of 'tramps' are 'TAP'.
(Other definitions for tap that I've seen before include "Gentle stroke" , "Water controller" , "Make use of; water from it" , "water supply" , "Dancing" .)