Crossword Genius

Gutted French fish produces toxin (6)

Ross

I believe the answer is:

poison

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'toxin' is the definition.
(I've seen this before)

I don't understand the remainder of the clue.

Can you help me to learn more?

(Other definitions for poison that I've seen before include "Damaging stuff - drink?" , "Toxic substance" , "[ADDER] 's defence" , "Corrupt" , "Dangerous substance" .)

I've seen this clue in The Sun.
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