One about to enter college line (6)
I believe the answer is:
policy
'line' is the definition.
(I know that policy is a type of line)
'one about to enter college' is the wordplay.
'one about' becomes 'ic' (I can't justify this - if you can you should give a lot more credence to this answer).
'to enter' indicates putting letters inside.
'college' becomes 'poly' (polytechnic).
'ic' inserted within 'poly' is 'POLICY'.
Can you help me to learn more?
(Other definitions for policy that I've seen before include "Course of action proposed in a political manifesto" , "Adopted principle" , "Insurance contract" , "Plan of action adopted by an individual or group" , "Plan of action - insurance document" .)