Polish almost off new shoe (4-2)
I believe the answer is:
slip-on
'shoe' is the definition.
(I know that slip-on is a type of shoe)
'polish almost off new' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'off' indicates an anagram.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'polish' with its final letter taken off is 'polis'.
'polis' anagrammed gives 'slipo'.
'slipo'+'n'='SLIP-ON'
(Other definitions for slip-on that I've seen before include "Shoe without laces" , "Not a lace-up" , "Shoe without fasteners" , "Garment or shoe with little or no fastening" , "Without fastening" .)