Fleming's creation put down evil in a lot of killing for the CIA (10)
I believe the answer is:
penicillin
'the cia' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'fleming's creation put down evil in a lot of killing' is the wordplay.
I cannot really understand how this works, but
'down' could be 'ill' (I've seen this in another clue) and 'ill' is found in the answer.
'in' is within the answer.
'lot' could be 'c' and 'c' is found within the answer.
The remaining letters 'peni' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'for' acts as a link.
Can you help me to learn more?
(Other definitions for penicillin that I've seen before include "17" , "Common antibiotic" .)