Broadcaster spoke out, initially ignoring America (5)
I believe the answer is:
radio
'broadcaster' is the definition.
(radios broadcast signals)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for radio that I've seen before include "Sound broadcasting" , "Part of the broadcasting industry" , "Contact" , "It used to be called the wireless" , "Communicate with" .)