One escaping hammer freely released at last (5)
I believe the answer is:
fleer
'one escaping hammer freely' is the definition.
The definition suggests a singular noun which matches the answer.
'released at last' is the wordplay.
'released' becomes 'leer' (I can't explain this - if you can you should give a lot more credence to this answer).
'at' is a charade indicator (letters next to each other) (I've seen this in other clues).
'last' becomes 'f' (I've seen this in other clues).
'leer' put after 'f' is 'FLEER'.
Can you help me to learn more?
(Other definitions for fleer that I've seen before include "mocking laugh" , "Fugitive" .)