Bores head back north and get lost regularly (7)
I believe the answer is:
tunnels
'bores' is the definition.
(bore can mean to drill or tunnel)
'head back north and get lost regularly' is the wordplay.
'head back north' becomes 'tun' (I can't explain this - if you can you should give a lot more credence to this answer).
'and' becomes 'n' (common abbreviation for 'and').
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'get'+'lost'='getlost'
The alternating letters of 'getlost' are 'els'.
'tun'+'n'+'els'='TUNNELS'
(Another definition for tunnels that I've seen is " Underground passages".)