Fish heart spurned by talk show host (4)
I believe the answer is:
opah
'fish' is the definition.
(opah is a kind of fish)
'heart spurned by talk show host' is the wordplay.
I cannot really see how this works, but
'heart' could be 'h' (card game abbreviation) and 'h' is found within the answer.
The remaining letters 'opa' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for opah that I've seen before include "Kingfish" , "Ocean swimmer" , "Large deep-sea fish" .)