Nugatory horror film introduced by dance show pro (8,3,3,5)
I believe the answer is:
strictly for the birds
'nugatory horror film introduced by dance show pro' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.
'film introduced by dance show pro' is the wordplay.
'film' becomes 'The Birds' (Alfred Hitchcock film).
'introduced by' is a charade indicator (letters next to each other).
'dance show' becomes 'strictly' (I can't explain this - if you can you should give a lot more credence to this answer).
'pro' becomes 'for' (I've seen this before).
'strictly'+'for'='strictlyfor'
'thebirds' put after 'strictlyfor' is 'STRICTLY FOR THE BIRDS'.
Can you help me to learn more?
(Other definitions for strictly for the birds that I've seen before include "not worth bothering about - with 18d,29a,13a" , "Trivial" , "absolutely not to be taken seriously" , "Tree-top accommodation, for example, is" , "Dancing when one can fly" .)