One of those on the radio with headphones briefly in charge of one of those likely to blow top (8)
I believe the answer is:
volcanic
'one' is the definition.
Both the answer and definition are adjectives. Perhaps there's a link between them I don't understand?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for volcanic that I've seen before include "Of Etna etc" , "Liable to erupt" , "Liable to violent outbursts" , "Like pumice" , "Explosively unstable, rock say" .)