Poisonous
Part of speech: adjective
Definition: Containing sufficient poison to be dangerous
Venomous
Part of speech: adjective
Definition: Full of venom.Toxic; poisonous.Noxious; evil.Malignant; spiteful; hateful.Producing venom in glands or accumulating venom from food.
Example sentence: Well, there are without doubt species of jellyfish around the world that are potentially lethal to human beings, some of which shut beaches for entire seasons. The box jellyfish of Australasia is officially the world's most venomous creature, and has killed swimmers in the past.