Gather right before a line for security (10)
I believe the answer is:
collateral
'for security' is the definition.
(collateral is a kind of security)
'gather right before a line' is the wordplay.
I cannot really understand how this works, but
'gather' could be 'collate' (I've seen this before) and 'collate' is found in the answer.
'right' could be 'r' (common abbreviation) and 'r' is located in the answer.
'a' is present in the answer.
'line' could be 'l' (used when specifying particular lines from a poem) and 'l' is present in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for collateral that I've seen before include "subsidiary" , "Security for loan repayment; secondary" , "Something pledged as security for a loan" , "Aside from the main issue" , "Guarantee" .)