Carbon monoxide chokes air in Arab city (5)
I believe the answer is:
cairo
'arab city' is the definition.
'Cairo' can be an answer for 'city' (Cairo is an example). I am not certain of the 'arab' bit.
'carbon monoxide chokes air' is the wordplay.
'carbon monoxide' becomes 'CO' (chemical formula for carbon monoxide).
'chokes' is an insertion indicator.
'co' enclosing 'air' is 'CAIRO'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for cairo that I've seen before include "Port upstream from the Nile delta" , "Capital of Egypt" , "Egyptian capital" , "Capital city on the Nile" , "Al Qahira" .)