Nothing found in defective crumpet processor (8)
I believe the answer is:
computer
'processor' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe you can see a link between them that I don't see?
'nothing found in defective crumpet' is the wordplay.
'nothing' becomes 'O' (looks like zero - 0).
'found in' indicates putting letters inside.
'defective' is an anagram indicator.
'crumpet' with letters rearranged gives 'cmputer'.
'o' going inside 'cmputer' is 'COMPUTER'.
Can you help me to learn more?
(Other definitions for computer that I've seen before include "Eg, PC" , "Laptop, perhaps" , "Electronic machine, basis of networks" , "Electronic calculator" , "Comer put out by data processing machine" .)