Poisonous
Part of speech: adjective
Definition: Containing sufficient poison to be dangerous
Toxic
Part of speech: adjective
Definition: Having a chemical nature that is harmful to health or lethal if consumed or otherwise entering into the body in sufficient quantities.
Example sentence: Envy, propelled by fear, can be even more toxic than anger, because it involves the thought that other people enjoy the good things of life which the envier can't hope to attain through hard work and emulation.