Heavy garment and other things wrapping one in a little bit (9)
I believe the answer is:
greatcoat
'heavy garment' is the definition.
'other things wrapping one in a little bit' is the wordplay.
'other things' becomes 'etc' (I've seen this in other clues).
'wrapping' indicates putting letters inside.
'one' becomes 'a'.
'in' indicates putting letters inside.
'a little bit' becomes 'groat' (historical term for a small amount).
'etc' going around 'a' is 'eatc'.
'eatc' going within 'groat' is 'GREATCOAT'.
'and' acts as a link.
(Other definitions for greatcoat that I've seen before include "Long overgarment" , "Military outer wear" , "piece of clothing" , "what a soldier might wear" , "Long heavy outer garment" .)