Bioterrorism is when a person or group uses bacteria, viruses, or toxins from living things as a weapon — not mainly to win a battle between armies, but to frighten people and push a political aim. Spreading anthrax powder, or threatening to release a disease, would be this. It is a news and security word, almost never used in ordinary chat. Though actually the line is messy: a government doing the same thing in war is usually called biological warfare, not bioterrorism; the word “terror” points to fear used as a political tool, often by a group rather than a regular army. It is also not the same as a disease that spreads by accident. The point is purpose: someone uses the germ on purpose. People also say “biological terrorism,” which means the same.