Boot bag (4)
I believe the answer is:
sack
I believe this is a double definition.
'boot' is the first definition.
(I've seen this before)
'bag' is the second definition.
(I know that bag can be written as sack)
(Other definitions for sack that I've seen before include "Receptacle" , "Plunder; wine; bag" , "destroy > 50s dress" , "It carries coal" , "Flour or grain bag" .)