One ahead on course to remain secluded (4,2)
I believe the answer is:
hole up
'remain secluded' is the definition.
(I've seen this in another clue)
'one ahead on course' is the wordplay.
I cannot quite see how this works, but
'ahead' could be 'up' (similar in meaning) and 'up' is present in the answer.
'course' could be 'e' and 'e' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'to' acts as a link.
Can you help me to learn more?
(Another definition for hole up that I've seen is " Hide oneself".)