Go to Gretna Green with energy and mad Pole (5)
I believe the answer is:
elope
'go to gretna green' is the definition.
(I've seen this in another clue)
'energy and mad pole' is the wordplay.
'energy' becomes 'e' (physics symbol as in E=mc2).
'and' means one lot of letters go next to another.
'mad' indicates anagramming the letters.
'pole' with letters rearranged gives 'lope'.
'e'+'lope'='ELOPE'
'with' is the link.
(Other definitions for elope that I've seen before include "Run away to Gretna Green?" , "Run off with Mr/Ms Right" , "Run away with one's beloved" , "leave with lover" , "Run away secretly to marry" .)