Connected to ground seen within near the dyke (7)
I believe the answer is:
earthed
'connected to ground' is the definition.
'within near the dyke' is the wordplay.
'within' says the answer is hidden in the clue.
'EARTHED' is hidden in the letters of 'near the dyke'.
'seen' is the link.
(Other definitions for earthed that I've seen before include "attached to the ground" , "grounded" , "protected from shock" .)