Biodefense is a term used to describe protective measures and preparations against the threat of biological weapons and naturally occurring disease outbreaks. There are several synonyms that can be used interchangeably with the word biodefense, including biosecurity, biosafety, and biomedical defense. Each of these words is closely related to the field of biodefense and is used to describe the development and implementation of tools and technologies to safeguard against biological threats. Other synonyms include biological defense, medical countermeasures, and public health emergency preparedness. Regardless of the term used, the goal of biodefense is to keep individuals and communities safe and healthy in the face of biological threats.