poisonous
adj.-
1 dangerous to eat or touch (adj.) B1 Intermediatedescribes something that contains a substance that can cause illness or death if it enters your body.
containing or producing a substance that causes injury, illness, or death when absorbed or ingested.
ExampleBe careful not to eat those berries because they are poisonous.
ExampleThe bright colours of certain tropical frogs serve as a warning to predators that their skin is highly poisonous.
UsageOften used with 'to' to indicate who is at risk, such as 'poisonous to humans'.
PitfallThe snake is poisonous.The snake is venomous.In technical English, 'poisonous' means it hurts you if you eat it; 'venomous' means it hurts you if it bites you. However, many people use 'poisonous' for both in casual speech.
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2 harmful or unpleasant (adj.) B2 Upper Intermediatedescribes a person, feeling, or situation that is very negative and harmful to others.
extremely unpleasant, malicious, or harmful in a figurative sense; often applied to social atmospheres or interpersonal relationships.
ExampleHe decided to leave the company because of the poisonous atmosphere in the office.
ExampleThe politician's poisonous rhetoric served only to further divide the community during the election cycle.
Teacher's tipThis figurative sense is very common in modern workplace and relationship discussions, often interchangeable with 'toxic'.
From Middle English poisounous, poysonouse. By surface analysis, poison + -ous.