Edgy prisoner devours each fruit (4)
I believe the answer is:
pear
'fruit' is the definition.
(pear is a kind of fruit)
'edgy prisoner devours each' is the wordplay.
'edgy prisoner' becomes 'pr' (I can't explain this - if you can you should give a lot more credence to this answer).
'devours' indicates putting letters inside (inserted letters are devoured).
'each' becomes 'ea' (abbreviation).
'pr' placed around 'ea' is 'PEAR'.
Can you help me to learn more?
(Other definitions for pear that I've seen before include "Cider-making fruit" , "Orchard fruit" , "William, maybe" , "Conference, perhaps" , "Cone-shaped fruit" .)