A Pole employed by one casting Hook? (7,3)
I believe the answer is:
fishing rod
'one casting hook?' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'a pole employed by' is the wordplay.
'a pole' becomes 'rod' (synonyms).
'employed' becomes 'fishing' (I can't explain this - if you can you should give a lot more credence to this answer).
'by' is a charade indicator (letters next to each other).
'rod' after 'fishing' is 'FISHING-ROD'.
Can you help me to learn more?
(Other definitions for fishing rod that I've seen before include "Angler's pole" , "Angler's equipment" .)