Look to go north or south (4)
I believe the answer is:
peep
'look' is the definition.
(peep is a kind of look)
'go north or south' is the wordplay.
'go' becomes 'pee' (both can mean to urinate).
'north or south' becomes 'p' (I am not sure about this - if you are sure you should believe this answer much more).
'pee'+'p'='PEEP'
'to' is the link.
Can you help me to learn more?
(Other definitions for peep that I've seen before include "Take quick look" , "Secret look" , "Look slyly" , "Look furtively or voyeuristically" , "Look furtively (either way)" .)