In America, it occupies some of the radio waves (4)
I believe the answer is:
iowa
'in america' is the definition.
(I know that Iowa is a U.S. state)
'of the radio waves' is the wordplay.
'of' indicates the answer is hidden within the clue.
'IOWA' is hidden in the letters of 'the radio waves'.
'it occupies some' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for iowa that I've seen before include "State of USA" , "Central US state" , "US swing electoral state" , "US state, capital Des Moines" , "US state, three vowels" .)