Food store, being very low, reportedly delivers (4-6)
I believe the answer is:
deep-freeze
'food store' is the definition.
(I've seen this before)
'very low reportedly delivers' is the wordplay.
'very low' becomes 'deep' (eg a deep voice).
'reportedly' shows a homophone (sound like).
'delivers' becomes 'frees' (both can mean to rescue).
'frees' is a homophone of 'freeze'.
'deep'+'freeze'='DEEP-FREEZE'
'being' is the link.
(Other definitions for deep-freeze that I've seen before include "Store in ice" , "Store at a very low temperature" , "Refrigerator cabinet" , "Large iced food store" , "Cold food storage unit" .)