Initially plans to use beasts of burden for mountain paths (6)
I believe the answer is:
passes
'initially plans' is the definition.
Although both the answer and definition are verbs in their -s form, I can't see how one could define the other.
'beasts of burden for mountain paths' is the wordplay.
'beasts of burden' becomes 'asses' (I've seen this before).
'for' means one lot of letters go next to another (I've seen this in other clues).
'mountain paths' becomes 'p' (I can't justify this - if you can you should give a lot more credence to this answer).
'asses' put after 'p' is 'PASSES'.
'to use' is the link.
Can you help me to learn more?
(Other definitions for passes that I've seen before include "Moves like mountain gaps" , "Written permissions for absences" , "'Men seldom make . . . at girls who wear glasses'" , "Documents indicating permission" , "goes beyond" .)