The most common and most likely answer to this crossword clue is the 8 letter word PHONE-IN
I've seen this crossword clue in Independent
P
H
O
N
E
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N
More clues leading to the result PHONE-IN
Buddy explains!
The straight part
We know that "radio show" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case radio show = phone-in.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PHONE-IN mean?
PHONE-IN noun- A show requiring members of the public to telephone the studio.