Students have to copy neck of jacket (5)
I believe the answer is:
lapel
'neck of jacket' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe there's a link between them I don't understand?
'students have to copy' is the wordplay.
'students' becomes 'll' (an abbreviation for learner driver written twice).
'have' is an insertion indicator.
'to copy' becomes 'ape' (ape can mean to copy or imitate).
'll' going around 'ape' is 'LAPEL'.
Can you help me to learn more?
(Other definitions for lapel that I've seen before include "Feature of a jacket" , "Revere on a coat" , "Folded flap at front of jacket or coat" , "Turnover at the front of a coat" , "Lower part of collar on coat" .)