Poison counter (8)
I believe the answer is:
antidote
'poison counter' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe there's a link between them I don't understand?
'counter' is the wordplay.
I cannot really understand how this works, but
'counter' could be 'anti' (I've seen this in another clue) and 'anti' is found in the answer.
The remaining letters 'dote' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for antidote that I've seen before include "Counter to a poison" , "A remedy for poison (8)." , "Counteracting remedy" , "Counter-agent" , "Counteracting medicine" .)