Meaning of “poison” - Learner’s Dictionary

poison

verb [ T ] uk us /ˈpɔɪzən/
KILL

B2 to try to kill someone by giving them a dangerous substance to drink or eat:

He tried to poison his wife.
MAKE DANGEROUS

B2 to put poison or a dangerous substance in something:

They poisoned the city's water supply.
SPOIL

to make something very unpleasant:

These arguments were poisoning his life.
poison sb's mind

to make someone think bad things about someone or something:

Her father had poisoned her mind against me.
poisoned adjective

(Definition of “poison verb” from the Cambridge Learner’s Dictionary © Cambridge University Press)