Finding fag end in fancy cat food is a catastrophe (3,2,3)
I believe the answer is:
act of god
'catastrophe' is the definition.
(I know that act of God is a type of catastrophe)
'finding fag end in fancy cat food' is the wordplay.
I cannot quite understand how this works, but
'end' could be 'go' (going is a kind of ending) and 'go' is found within the answer.
an anagram of 'cat' is 'act' which is located in the answer.
'food' could be 'd' (D is an example) and 'd' is found in the answer.
The remaining letters 'of' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'is a' is the link.
Can you help me to learn more?
(Other definitions for act of god that I've seen before include "Bad result of natural force" , "An uncontrollable natural event, say an earthquake" , "Result of natural causes" , "deus ex machina?" , "Natural catastrophe - insurance company's get-out clause?" .)