Southern state, but not Iowa (7)
I believe the answer is:
austral
'southern' is the definition.
(similar in meaning)
'state but not iowa' is the wordplay.
I cannot really understand how this works, but
'state' could be 'us' (US is an example) and 'us' is present 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 austral that I've seen before include "Of the southern hemisphere" , "coming from Perth?" , "Southern - rat Saul (anag)" .)