Right position of course - north (4)
I believe the answer is:
lien
'right' is the definition.
(legal right)
'position of course north' is the wordplay.
I cannot quite understand how this works, but
'position' could be 'lie' (lie can mean to place or position) and 'lie' is present in the answer.
'course' could be 'n' and 'n' is found in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for lien that I've seen before include "Sequestration order" , "The right to take property if an obligation is not discharged" , "The right to take property if an obligation is not met" , "Security for a debt" , "Legal claim on the property of another" .)