poison
This word carries a heavy sense of betrayal or hidden danger. While toxins are biological and chemicals are industrial, poison suggests a targeted, often malicious application. It evokes the image of something appearing harmless on the surface while concealing a deadly interior. In a social or emotional sense, it describes a slow, corrosive influence. When a relationship is poisoned, it is not a sudden break but a gradual infiltration of bitterness or distrust that makes the environment uninhabitable.
Countable when referring to a specific type of toxic chemical (three different poisons). Uncountable when referring to the general substance or the quality of being toxic (the water contains poison).
Meanings
A substance that causes illness or death when absorbed or ingested.
"The spider's poison is lethal to small mammals."
To administer a toxic substance to someone or something.
"The villain tried to poison the king's wine."
To spoil or corrupt the quality or atmosphere of something.
"The scandal threatened to poison the entire political climate."