Copy between lines, collaring part (5)
I believe the answer is:
lapel
'part' is the definition.
(I have seen 'Part of jacket' mean 'lapel' so perhaps 'part' could also mean 'lapel')
'copy between lines collaring' is the wordplay.
'copy between' becomes 'ape' (ape can mean to copy or imitate. I am not sure about the 'between' bit.).
'lines' becomes 'll' (an abbreviation for line written twice).
'collaring' is an insertion indicator.
'ape' put inside 'll' is 'LAPEL'.
Can you help me to learn more?
(Other definitions for lapel that I've seen before include "Part of a suit jacket" , "Folded back part of jacket" , "Part of a folded back collar" , "top of coat" , "Fold of coat" .)