Feature of shirt left in wrapper (7)

'wrapper' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps you can see an association between them that I can't see?

'feature of shirt left' is the wordplay.
I cannot really understand how this works, but
'shirt' could be 't' (as in a T-shirt) and 't' is located in the answer.
'left' could be 'l' (common abbreviation) and 'l' is present in the answer.
'feature' could be 'pack' (packing is a kind of featuring) and 'pack' is found in the leftover letters.
A single letter 'e' remains which might be clued in a way I don't see.
This explanation may well be incorrect...

'in' is the link.

Can you help me to learn more?