Furtive investigation into dangerous poison I spat out (5)
I believe the answer is:
snoop
'out' is the definition.
The answer and definition can be both to do with communicating as well as being verbs in their base form.
Perhaps they are linked in a way I don't understand?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for snoop that I've seen before include "-- Dogg, US rapper; spy" , "Stick one's nose in" , "Be nosy" , "Investigate; pry" , "Furtively investigate" .)