Decipher flesh file to reveal how long something remains usable (5,4)
I believe the answer is:
shelf life
'long something remains usable' is the definition.
I can't tell whether this defines the answer.
'decipher flesh file to reveal' is the wordplay.
'decipher' indicates an anagram (I've seen 'deciphering' mean this).
'to reveal' indicates an anagram.
'flesh' with letters rearranged gives 'shelf'.
'file' with letters rearranged gives 'life'.
'shelf'+'life'='SHELF LIFE'
'how' is the link.
Can you help me to learn more?
(Other definitions for shelf life that I've seen before include "Period for which item is saleable" , "Time for which item remains saleable in shop" , "Period in which article is for sale" , "time when still fresh" , "Period for which a stored item remains usable" .)