Head pulled up lining of nice jacket (5)
I believe the answer is:
tunic
'nice jacket' is the definition.
'tunic' can be an answer for 'jacket' (I've seen this before). I am not certain of the 'nice' bit.
'head pulled up lining' is the wordplay.
'head' becomes 'nut' (informal term for somebody's head).
'pulled up' says the letters should be written in reverse.
'lining' becomes 'ic' (I can't explain this - if you can you should believe this answer much more).
'nut' in reverse letter order is 'tun'.
'tun'+'ic'='TUNIC'
'of' is the link.
Can you help me to learn more?
(Other definitions for tunic that I've seen before include "Policeman may be in one" , "Schoolgirl's dress" , "Upper garment, for a soldier say" , "piece of clothing" , "Close-fitting jacket that's part of a uniform" .)