School in Cardiff is horrendous (4)

I believe the answer is:

fish

'school' is the definition.

'in cardiff is horrendous' is the wordplay.
'in' indicates a hidden word.
'FISH' is hidden within 'cardiff is horrendous'.

(Other definitions for fish that I've seen before include "Ruff" , "Weatherman" , "Customer" , "To try to catch" , "Aquarium" .)

I've seen this clue in The Telegraph.

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