Grain featuring in a long running radio show (6)
I believe the answer is:
cereal
'grain' is the definition.
(I know that cereal is a type of grain)
'a long running radio show' is the wordplay.
I cannot quite see how this works, but
'a' is found in the answer.
'long' could be 'l' and 'l' is located in the answer.
The remaining letters 'cere' is a valid word which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).
'featuring in' is the link.
Can you help me to learn more?
(Other definitions for cereal that I've seen before include "11 food, maybe" , "Relating to grain" , "Common part of breakfast" , "Breakfast dish" , "Eg, 5 Ac" .)