Agitated gent left nitrogen compound and metal (4)
I believe the answer is:
iron
'metal' is the definition.
(iron is a kind of metal)
'agitated gent left nitrogen compound' is the wordplay.
I cannot really understand how this works, but
'gent' could be 'ron' (short for Ronald) and 'ron' is present in the answer.
A single letter 'i' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
'and' is the link.
Can you help me to learn more?
(Other definitions for iron that I've seen before include "1 down, symbol Fe" , "Magnetic metallic element" , "Wellington was known as the .... Duke" , "Heavy metallic element" , "resolve" .)