Remained sober in radio broadcast (6)
I believe the answer is:
stayed
'remained' is the definition.
('stay' can be a synonym of 'remain')
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for stayed that I've seen before include "Tarried" , "Hung about" , "Continued" , "Remained or deferred" , "Supported" .)