Nail bent round an angle, used by the smith (5)
I believe the answer is:
anvil
'nail bent round' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'an angle used by the smith' is the wordplay.
'angle' becomes 'l'.
'used by' means one lot of letters go next to another.
'the smith' becomes 'vi' (I can't justify this - if you can you should give a lot more credence to this answer).
'l' put after 'vi' is 'vil'.
'an'+'vil'='ANVIL'
Can you help me to learn more?
(Other definitions for anvil that I've seen before include "Block on which metal can be hammered" , "Forging equipment" , "part of the ear" , "Smithy's last" , "Block for blacksmith" .)