An animal that is poisonous produces a poison that will kill you or make you ill if the animal bites you. There are hundreds of poisonous spiders and snakes
If you describe something as poisonous, you mean that it is extremely unpleasant and likely to spoil or destroy a good relationship or situation. poisonous comments
marked by deep ill will; deliberately harmful; "a malevolent lie"; "poisonous hate in his eyes"- Ernest Hemingway; "venomous criticism"; "vicious gossip"
Having the qualities or effects of poison; venomous; baneful; corrupting; noxious
Something that is poisonous will kill you or make you ill if you swallow or absorb it. a large cloud of poisonous gas