natural toxin; naturally occurring poison
Refers to toxic substances produced by living organisms, such as plants, animals, fungi, or bacteria, as opposed to synthetic chemicals.
Food poisoning caused by natural toxins in mushrooms is reported every year.
The natural toxin in pufferfish is dangerous if not properly prepared.
Compound of 自然 (しぜん, 'nature') and 毒 (どく, 'poison').