Enthusiasm for glum sitcom that's shown regularly (5)
I believe the answer is:
gusto
'enthusiasm' is the definition.
(gusto is a kind of enthusiasm)
'for glum sitcom that's shown regularly' is the wordplay.
I cannot really see how this works, but
'for' could be 'to' (eg both can mean 'in the opinion of') and 'to' is found within the answer.
The remaining letters 'gus' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for gusto that I've seen before include "Energy" , "Verve, zest" , "Spirit" , "Got us with great enjoyment" , "Zest and enjoyment in doing something" .)