What the merchants are squabbling about? (5,4)
I believe the answer is:
scrap iron
'what the merchants' is the definition.
I can't judge whether this definition defines the answer.
'are squabbling about?' is the wordplay.
I cannot quite see how this works, but
'are' could be 'a' (short for 'are', historical unit of measurement) and 'a' is located in the answer.
'about?' could be 'on' (as in a book 'on' a certain topic) and 'on' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for scrap iron that I've seen before include "rubbish" , "for recycling" , "Discarded metal" , "Waste metal for melting down" .)